WASHINGTON — President Donald Trump arrives this week on Capitol Hill to deliver a speech to Congress, a coequal branch of government he has bulldozed past this first month in office, wielding unimaginable executive power to get what he wants, at home and abroad.

Tonight’s address will unfold in the chamber where lawmakers crouched in fear four years ago while a mob of his supporters roamed the halls, and where Nancy Pelosi, Liz Cheney and others vowed to prevent him from ever holding office again. It’s the same House chamber where Ukrainian President Volodymyr Zelenskyy received a hero’s welcome for fighting off Russia’s invasion, in the first year of that war.

Since his reelection, Trump has blazed across the federal government, dismantling not just norms and traditions but the very government itself. With billionaire aide Elon Musk by his side, he is firing thousands of federal workers, closing agencies established by law and publicly badgering Zelenskyy while positioning the U.S. closer to Russia.

More than 100 so far challenging the legality of the Trump administration’s actions, the Republican president is daring the other branches of government — Congress and the courts — to try to stop him.

“This whole thing about approaching a constitutional crisis is not quite true,” said Rep. James Clyburn, of South Carolina, a senior Democrat in the House. “We’re already there.”

Trump revels in going it alone, but there are limits

Reveling in the might of going it alone, Trump is about to test the limits of his executive branch authority as he turns to Congress to deliver tax cuts and other key aspects of his agenda. Only Congress, by law, can allocate funds — or pull them back — but the Trump administration’s actions have been testing that foundational rule, enshrined in the Constitution.

Trump also needs lawmakers to fund the government and ensure federal operations don’t shut down when money runs out March 14. And he will need Congress to pass legislation to prevent an economically damaging debt default, something he has pushed lawmakers to resolve.

While Trump enjoys the rare sweep of power in Washington, with the Republicans controlling the White House, the House and the Senate, he relies on political fear as well as favor to motivate lawmakers. With Musk having poured $200 million into electing Trump, the president has a ready patron whose vast political funds can influence any resisters.

Democrats, after their stunning rejection by voters, are slowly beginning to mount a resistance. They are fighting Trump in court, with amicus briefs to protect federal workers, and filing legislation to serve as a check on what House Democratic leader Hakeem Jeffries of New York calls the “parade of horribles.”

But as the minority party, they are limited in their power. Jeffries brushed off calls for Democrats to boycott Trump’s address. “It’s the people’s House. It’s the House of Representatives,” he said on CNN.

One of Trump’s top campaign promises, extending the tax breaks approved during his first term in 2017, is posing one of his party’s biggest challenges.

Johnson and Senate Majority Leader John Thune of South Dakota are marshalling the GOP majority to deliver what Trump calls a “big, beautiful bill” extending those tax breaks — and providing new ones. But Republicans also want some $2 trillion in budget cuts with changes to Medicaid and other services that millions of Americans count on, which Trump could decide is too much to bear.

Trump’s other big campaign promise — the biggest deportation operation in U.S. history — is running short of cash, and border czar Tom Homan has implored Republicans on Capitol Hill to loosen the purse strings to give the Homeland Security and Defense departments the money needed.