And on the seventh day he golfed. But before that . . .

President Trump called for an investigation of a former FBI director. He eliminated health insurance subsidies for low-income Americans. He prompted outrage in Great Britain by charging that an increase in crime there was a result of Islamic terrorism. He criticized the National Football League on the issue of players taking a knee during the national anthem. He vilified a congresswoman and criticized the widow of a US Army sergeant killed in Niger. He urged the Senate Intelligence Committee to investigate ‘’the Fake News Networks in OUR country to see why so much of our news is just made up — FAKE!’’ He derided what he called the “phony Trump/Russia ‘collusion’ which doesn’t exist’’ and argued that Democrats were conducting a witch hunt and practicing “evil politics.’’ He declared the opioid crisis a health emergency.

That is only a tiny fraction of what Trump — the nation’s chief executive and most celebrated tweeter — did in only a month’s time this fall. Any one of those events might have stood out even in a crowded four-year term, but they are mere wallpaper in our civic life today — seldom remarked upon, swiftly forgotten, lost in the blur that Americans have had to grow accustomed to in one of the most frantic and frenetic presidential years in history.

“I don’t think we’ve ever had a president make news like this president makes news,’’ said G. Calvin Mackenzie, an emeritus political scientist at Colby College. “He gets up every morning and makes news — often outrageous news, but it is news.’’

Trump’s ascendancy in a year with multiple mass shootings, fears of nuclear war, three deadly hurricanes, an explosion of sexual harassment charges, and tectonic changes in the United States’ relations with its allies makes an old reflection by Vladimir Ilyich Lenin, the Russian revolutionary and rapid-fire history maker, sound like understatement: “There are decades where nothing happens — and there are weeks where decades happen.’’

This has been a year made up of those kinds of weeks, with so many peak moments that few stand out. It is a year, perhaps, to feel a little pity for anyone charged with summing it up.

The 45th president has dominated the national conversation more than any other chief executive of modern times, perhaps even more than wartime presidents Abraham Lincoln and Franklin Delano Roosevelt. And yet it is weirdly hard to summon from memory any particular thing he said.

As a result, a president who said his country would grow “tired of winning’’ might look out from his White House windows today to see a country that is merely tired.

“The pace of news, and the lack of discipline of Trump’s message, have made for a certain fatigue,’’ said Andrew Rudalevige, a Bowdoin College political scientist. “Subjects that otherwise might be a big constitutional showdown are reduced to a two-day story after the president tweets something new about the NFL.’’

Prior presidents have faced crises of various kinds in their first year — political, economic, military, and racial challenges that produced an air of tumult in the White House and the nation. The difference is that the tumult in Trump’s first year came mainly from the president himself.

“There is tumult, but it is unforced tumult,’’ said Bruce Bartlett, a domestic policy adviser to Ronald Reagan and George W. Bush. “I can’t recall another president who came into office and gratuitously did so much stuff that wasn’t driven by external events.’’

That perhaps is a result of having a political newcomer in the White House surrounded by a staff with little political experience.

“There are a lot of rookies on the Trump team,’’ said Andrew H. Card, White House chief of staff in the George W. Bush administration. “They almost had a predisposition that they didn’t want anybody who had been in the swamp. But they should have known that if you go into a swamp, you don’t want to go in without any guides.’’

The self-guided dynamo that is Trump doesn’t take the road less traveled by, but rather seems inclined to barrel down every way at once. And that has made quite the difference, both fans and his critics say. “The country needs a leader who is calm under pressure, who is controlled and who can see through the chaos rather than stoke the chaos,’’ said US Representative Seth Moulton, a Marblehead Democrat who is clearly no fan. “Trump fundamentally is not that kind of leader. He has no values, no guiding principles, no recognition that it is the job of leaders to rise above the fray for people and for the country.’’

“He’s in a hurry because he’s led his life in a hurry,’’ said US Representative Mike Kelly, a Republican and Trump admirer whose district north and east of Pittsburgh voted for the president by a landslide 61-35 percent margin. “He wants things to happen now, not later.’’

More than even his immediate and far younger predecessor, Barack Obama (born in 1961 in the chill of the Cold War), Trump (born just after World War II in 1946) is a thoroughly modern president, harnessing the communications technology of the age even as he defines it. In that sense, the president is a logical extension of FDR, who transformed the radio into a powerful persuasive tool, and John F. Kennedy, whose mastery of television helped him win the 1960 election and then, in televised press conferences and set-piece Oval Office remarks, inform, calm, amuse, and mobilize the American people.

“The winning candidates in presidential elections are the ones who understand the new technology the best,’’ said Diane S. Rubenstein, a Cornell political scientist. “The tweet has become Trump’s primary way of communicating.’’

Perhaps reflecting his personal impulsiveness, perhaps reflecting the temper of the times, Trump dives into Twitter almost daily, sometimes many times a day. Many of his predecessors sought to maximize the power of their words by doling them out sparingly or staying above the fray. FDR, referring to his famous fireside chats, once cautioned that less can be more, that the public cannot “be attuned for long periods of time to the constant repetition of the highest note in the scale.’’ Trump, by contrast, is profligate with commentary. He relishes the high notes. He is the fray.

“There’s nothing Donald Trump won’t comment on, and there’s almost nothing earlier presidents would comment on,’’ said Amity Shlaes, the most recent biographer of Calvin Coolidge, the former Massachusetts governor who as president was known more for his silence than for his public remarks. “Long ago, presidents withheld comments from the press and were considered fools if they did not.’’

All presidents, even those who cultivate allies in the press corps, come to resent the press, but Trump’s frustration with it came especially early in his term and is expressed with special venom. Indeed, the president has made the mainstream news media a special target of opprobrium, regularly challenging their reporting and dismissing negative stories as ‘’fake news.’’ The definition of “fake’’ seems to be simply news he doesn’t like.

“Trump has taken the idea that you make your own reality to an extreme,’’ said Rubenstein, who studies what she calls the post-modern presidency.

That tendency in him has kindled a huge debate in newsrooms and living rooms about the credibility of journalists, a debate with enormous implications because it comes at a time when the mainstream media is also under remorseless financial stress.

Three weeks ago, Trump tweeted a characteristically scorching critique: “Very little discussion of all the purposely false and defamatory stories put out this week by the Fake News Media. They are out of control — correct reporting means nothing to them. Major lies written, then forced to be withdrawn after they are exposed . . . a stain on America!’’

Richard Nixon, the most famous press-loather among recent presidents, never said anything like that — at least not for the world to hear.

All these presidential tweets and attacks on the press have come amid fundamental shifts in the American way of relating to and responding to presidential leadership, the structure of the political parties, perhaps even in the nation’s character. The impact of these will only become clear in the years and decades ahead, and some, to be sure, were in progress before Trump took office. But in a remarkably short space in time, he has accelerated and amplified these trends.

Bipartisanship, long ailing, now seems dead.

Obama won his health care overhaul without a single vote from the opposition party, so it was almost unremarkable that the tax overhaul signed into law by Trump this month proceeded without the support of a single Democratic lawmaker.

The Republicans were determined to endanger the Obama presidency eight years ago, and the Democrats, with impeachment in their thoughts if not quite yet on their lips, are determined to topple the Trump presidency.

One impulse of intransigence begat another.

“Trump and our current political situation is the product of a long process of the coarsening of our politics,’’ said Thomas J. Whalen, a Boston University political scientist. “It left an opening for an outsider without respect for the political process to emerge, because the people inside the political process had no respect for each other.’’

The tax bill that dominated December provides a clear window into many of the vital changes that have swept through Washington. Thirty-two years ago, Republicans and Democrats worked together to overhaul the tax code, a joint effort that engaged both sides so thoroughly that Representative Dan Rostenkowski, the Illinois Democrat who headed the House Ways and Means Committee, and Senator Bob Packwood, the Oregon Republican who headed the Senate Finance Committee, were allies rather than combatants.

“The cooperation we had is a thing of the past, and it shows,’’ Packwood reflected in an interview this month.

The partisan warfare —perhaps more vicious than at any time in the past century and a half of American politics — is both cause and consequence of the Trump ascendancy. Not since the Reconstruction years, when Democrats fought with Republicans and when Radical Republicans fought with moderate Republicans, has the political landscape seemed so complex, so conflicted, and so dangerous.

Trump has dismissed the Senate Democratic leader, Chuck Schumer of New York, as a “clown,’’ but also has not hesitated to excoriate the Republican leader, Mitch McConnell of Kentucky. Democrats have been united in their opposition to almost every Trump initiative, but Republicans have been divided — a division that veteran party theorists believe may have serious consequences.

“Trump was never a Republican,’’ said former representative Mickey Edwards of Oklahoma, a Republican himself, who was a founding trustee of the conservative Heritage Foundation and a lecturer at Harvard’s Kennedy School of Government. “But when you see Republicans lining up with him on so many things you begin to wonder what the party has become.’’

Is it, for example, the lineal extension of the Bob Taft Republicans, rooted in the Midwest and in their opposition to the New Deal? Is it the legatee of the flinty Coolidge/Bob Dole party, steeped in thrift, wary of debt, above all skeptical of showboats and self-promoters? Is it the descendant of the John Foster Dulles/George H.W. Bush strain of Republicans, committed to patrician notions of service and vigorous engagement in the world? Is it the extension of the Patrick J. Buchanan school, wary of international commitments, fond of political pugilism, and engaged in a cultural war with liberalism?

Or is it somehow all of the above?

Whatever the answer, the indisputable truth is that Trump is both a product and a definer of his day — a populist at a time when technology has democratized many elements of the culture, especially the media, which is no longer the exclusive province of newspaper publishers and broadcast networks.

He is a warrior against political correctness at a time when a liberal-oriented mass culture congenial to minorities and alternative lifestyles prevails, on campus, on the coasts, and in many urban enclaves. He is an unrepentant nationalist at a time when business and communications are increasingly global, and above all, he is a disrupter at a time when everything — music, news, merchandising, banking, higher education, travel, even religion — is being disrupted.

“It’s not only that he is using new technology to reach beyond the traditional group of people interested in public policy,’’ said Dora Kingsley Vertenten, who teaches at the Price School of Public Policy at the University of Southern California. “He also has no working knowledge of the political process or the rules that determine how government works. We’re having a large-scale experiment to see if you can run government like a business.’’

As a result, even the tech-savvy former president Obama, often photographed with BlackBerry in hand, seems quaintly antiquarian in the age of Trump.

Trump, who broke so many barriers in winning the presidency, has crumbled even more in his first year in the White House. His approach to leadership, his refusal to conform to well-established norms of presidential behavior, and his cultivation of a culture of chaos, both inside the administration and in its public profile, have placed him apart from all his predecessors.

There have been insurgents and rebels in the presidency before — Andrew Jackson, for example, and Theodore Roosevelt — but Trump is alone in willfully and dramatically resisting the patterns of presidential comportment.

Historians have struggled to find a presidential precedent to Trump. Leslie J. Gordon, who holds an endowed chair in Southern history at the University of Alabama, argues that the best analog might be Andrew Johnson, who succeeded Lincoln after the Ford’s Theater assassination in 1865 and presided over an especially fractious time in American history.

“Johnson was somebody who lashed out easily, who picked personal fights, who was a wildcard for the Republican Party, which tried to control him but couldn’t,’’ she said. “I’m not saying Trump will be impeached, but like Andrew Johnson, he was a singular personality.’’

At the root of American politics today is not so much ideology as anger. That has been a leitmotif of US civic life in the past, but in the past, anger has seemed to be a transient quality, swept away by new prosperity or new personalities. Today, anger and intimidation seem to be permanent elements of our politics — and some analysts and practitioners believe that money is at the root of this shift, with the weight of opinion veering to the extremes of right or left, as big donors reward ideological compliance.

“I watched the culture of Congress change through the 1980s and 1990s as the importance of campaign contributions grew ever larger,’’ former vice president Al Gore Jr. said in an interview. “Today the average member of Congress spends four to five hours a day begging rich people and lobbyists for money to stockpile a war chest to intimidate their opponents. The effect is a weakening of democracy.’’

US Representative Rick Nolan of Minnesota has been a personal witness to this change. He also blames the chase for money — and the shortened congressional work week that developed as lawmakers traveled more in the pursuit of campaign funds — for a change in the tone of Congress, and for the lack of moderates who can work across the aisle.

“Moderates are becoming an endangered species, and that’s partly because of the egregious gerrymandering,’’ said Nolan, who first was elected in the post-Watergate Democratic landslide, then departed for 32 years — the largest such interregnum in congressional history — and returned five years ago. ‘’Districts are gerrymandered Democratic or Republican, and the contests are won mainly by the extremes of the bases. There’s not a whole lot of room for moderates on either side of the aisle.’’

The first year of the Trump administration has only deepened the bitterness on both sides of the partisan divide.

“If you look at issues and ideology, there is no change. The electorate looks the same as it always has,’’ said Morris P. Fiorina, a Stanford political scientist who studies political polarization. “But there are suggestions that Democrats and Republicans dislike each other more, perhaps because if you look at TV you see all these abnormal people screaming at each other. And we do know that Trump has taken positions — like tightening up the borders — that might strike people as reasonable if they weren’t associated with Trump.’’

An important element of the conflict in the Trump era revolves around allegations of ties between his presidential campaign and Russian efforts to tilt the election — the subject of several Washington investigations.

It is unusual for a president to begin his term facing these types of questions, and many of his most ardent critics clearly are hoping the results of the investigations will help end his tenure.

‘’When Nixon saw the end was inevitable and he would be impeached and likely convicted, he decided to resign,’’ Watergate prosecutor Richard Ben-Veniste said in an interview. “He recognized he had put the country through turmoil as a result of his actions and lying, and it was time to go.

“From many corners, there are controversies about Trump’s state of mind that are unprecedented,’’ he continued. “It is a matter of speculation as to what he would do if he or a member of his family were identified as a lawbreaker who deserved to be punished.’’

Much of that will become clear in the new year.

For many decades on New Year’s Eve, newspaper cartoonists portrayed the coming year as a newborn child and the fading year as a wizened old man. The more appropriate cartoon figure for 2017 might well be a stooped figure of exhaustion, fatigued not by noble battle but rather incessant, dispiriting conflict.

“I’ve got a great ambition to die of exhaustion rather than boredom,’’ wrote the 19th-century Scottish philosopher and essayist Thomas Carlyle, who is famous for his argument that history is the sum of the deeds of the great figures of their time. In this long year of convulsive change, boredom was the only thing missing.

David M. Shribman, executive editor of the Pittsburgh Post-Gazette, can be reached at dshribman@post-gazette.com.