WASHINGTON — President Donald Trump does not readily admit defeat. Knocked to the mat in Alabama with the stunning loss of a Senate seat, he got right back up on Wednesday and defiantly claimed that he had known his candidate would lose all along. He may have been humbled by voters, but Trump does not exactly do humble.

Aides to the temperamental president reported being pleasantly surprised that he did not rage against the setback in private, as he is wont to do in moments of difficulty. But neither did he concede a mistake in backing the Republican candidate, Roy Moore, despite sexual misconduct allegations, attributing the loss to Moore and the national party establishment that abandoned him.

All but ignoring the political earthquake in Alabama in public appearances Wednesday, Trump pushed forward with his drive for major tax cuts, giving little indication that he shared his party’s panic about potentially worse defeats to come in next year’s midterm congressional elections. While aides anticipate possible staff changes, Trump showed no signs of shifting from the strident, base-oriented politics that have animated his presidency.

“I don’t think it’s going to affect it,” Trump said of the election’s impact on his agenda as he met with Republican lawmakers writing the final version of his tax legislation. “I think we’re doing a lot. This is the biggest thing that we’ve worked on.”

Behind the scenes, some advisers hoped the loss would persuade Trump to stop listening to Stephen Bannon, his former chief strategist who has vowed war against the Republican establishment. But Trump talked with Bannon for 15 minutes by phone on Tuesday, aides said, and seemed disinclined to cut the adviser from his circle.

Nor was it clear that Trump was any more eager to reach across the aisle and build new coalitions with Democrats even as his party’s control of the Senate narrowed to a single seat. With Wednesday’s agreement on a final tax cut bill, Trump seems poised to push through his first major achievement after a year of legislative frustrations, but it remained uncertain how he would proceed after that.

“I think he’s going to have a compelling story to make that ‘my agenda is making the country better,'” said Matt Schlapp, the chairman of the American Conservative Union. But he recommended that Trump recruit Democrats for legislation on criminal justice and infrastructure. “I think the president and the administration should look for allies outside of the leadership as well — not in opposition to leadership — but there are other voices that might lead to a different coalition of members that would support their agenda.”

Trump flirted with bipartisanship in the fall when he cut a three-month spending deal with Sen. Chuck Schumer of New York and Rep. Nancy Pelosi of California, the Democratic leaders. But when he sought to extend that cooperation with an agreement to allow younger immigrants brought into the country illegally to stay, conservatives objected and he quickly retreated.

Other presidents have been knocked off stride by special elections that ultimately presaged greater defeats. In 1991, George Bush was stunned when his attorney general, Dick Thornburgh, lost a special election for Senate against Harris Wofford, a little-known Democrat whose strategists went on to help Bill Clinton topple the incumbent president a year later.

In 2010, Barack Obama was likewise thrown by the election of Scott Brown, a Republican, to fill a vacant Senate seat in heavily Democratic Massachusetts. The election not only cost Democrats their filibuster-proof supermajority just as they were trying to pass health care legislation, but it also foreshadowed a Republican landslide in midterm elections later that year.

Peter Baker and Maggie Haberman/The New York Times