Congress passed a law shutting down TikTok, and President Trump flouted it. Congress required advance notification for firing inspectors general, and the Trump administration ignored it. Congress approved trillions of dollars in spending on a multitude of federal programs, and Mr. Trump froze it.

The new administration is quickly demonstrating that it does not intend to be bound by the legal niceties or traditional checks and balances of its relationship with Congress. That has infuriated Democrats but drawn shrugs and approval from Republicans who say Mr. Trump is delivering what he promised even if it comes at the expense of Congress’s authority and constitutional status as a coequal branch of government.

“President Trump clearly ran for office to be a disrupter, and he’s going to continue to do that,” said Senator John Barrasso of Wyoming, the No. 2 Republican.

Mr. Trump is also clearly embarking on a test of what he can cow a Congress under total Republican control into swallowing. Early indications are that it will be a lot.

In addition to his attempt to snatch the power of the purse away from Congress, he has sent up a crop of high-level cabinet nominees who would have never passed muster on Capitol Hill in the past, daring Republicans to either back them or risk the wrath of the movement backing Mr. Trump. All but a few have snapped into line.