Some citizens of this republic will see Donald Trump’s second inauguration as a glorious new beginning; others will see it as a dispiriting surrender to the nation’s worst tendencies. Many commentators will surely conclude that this uncommonly frigid Monday in Washington defined the past decade, for better or worse, as the Trump Era.

Historians, however, might view Trump’s swearing-in through a wider lens: Jan. 20, 2025, could well be remembered as the apotheosis of a Second Gilded Age.

The times we live in echo the original Gilded Age, roughly from 1870 to 1900. Now, as then, wealth is increasingly concentrated in the hands of a very few. According to the St. Louis Federal Reserve, the richest 1 percent of Americans hold about 31 percent of the nation’s total wealth - up from 23 percent in 1990. The bottom 50 percent hold just 2.4 percent of total wealth. Let me repeat: The net worth of fully half of the U.S. population, in the aggregate, is just a tiny fraction of the net worth of the top 1 percent.

In the first Gilded Age, a few tycoons amassed unimaginable riches - men such as John D. Rockefeller, Cornelius Vanderbilt and J.P. Morgan. With their great wealth came great power and influence. When they spoke, presidents listened.

On Monday, as a billionaire reassumed the nation’s highest office, in attendance were the three wealthiest human beings on the planet, according to the Forbes and Bloomberg lists of billionaires: Elon Musk, Jeff Bezos (who owns The Post) and Mark Zuckerberg.

Musk spent an estimated $277 million last year to boost Trump’s campaign for the presidency. That money, far less than one one-thousandth of Musk’s net worth, bought him constant access to Trump at his Mar-a-Lago estate - and soon, reportedly, an office in the White House complex.

In his farewell address to the nation on Wednesday, President Joe Biden warned of the dangers of this concentration of wealth. “Today, an oligarchy is taking shape in America of extreme wealth, power and influence that literally threatens our entire democracy, our basic rights and freedoms, and a fair shot for everyone to get ahead,” Biden said.

Capitalism is the American way, and today’s tycoons should not be punished for being good at it - or for their inventions and innovations that have changed the way we live, creating millions of jobs. But upward mobility is also the American way, and government has an important role to play in making such mobility possible.

Trump connected with many voters who feel their current trajectory is downward, who no longer have the confidence that their children’s lives will be more affluent than their own. These voters put their faith in Trump to put them and their communities once again on a rising path.

But Trump promises to do the opposite: to double down on policies that have made the rich richer and the poor poorer.

Trump has repeatedly spoken of his admiration for President William McKinley, the last president of the Gilded Age. Elected in 1896, McKinley accommodated the super-rich “robber barons.” He protected U.S. industry with high tariffs; and he took no major action to regulate or break up monopolies that stifled competition. He also pursued expansionism, seizing Puerto Rico in the Spanish-American War and annexing the Republic of Hawaii.

Trump, too, has said he will impose steep tariffs on imported goods - which effectively will be a regressive tax that means little to the wealthy but takes money out of the pockets of the middle class and the poor. During his first term in office, he cut taxes for the rich; now, he promises to cut them again. And he plans to grant the business community’s fondest wish by drastically slashing oversight and regulation.

And as for manifest destiny, Trump has his eye on Greenland. (I seriously doubt he’ll get it.)

Under Trump’s hero McKinley, the concentration of wealth and power reached a peak. His successor, Theodore Roosevelt, reversed the nation’s course. He used the Sherman Antitrust Act of 1890 to break up monopolies and foster competition. He regulated the rates that railroads could charge for moving freight. He pushed Congress to pass legislation giving the federal government the power to enforce safety standards for food and drugs.

Roosevelt promised a “square deal” for everyday Americans. Trump portrays himself as a champion of the working class, but his policies and practices say otherwise. I’ll believe him when he stops trying to fleece his supporters by selling them $40 American flag flip-flops, $55 MAGA hats and ugly red $200 sneakers.

He’s back for what will be four long years. If you love everything about him, enjoy the ride. If you don’t, spend this time planning and working to bring the Second Gilded Age to its end.