WASHINGTON — When Donald J. Trump set his sights on the presidency in the 2000 election, he pursued the nomination of the Reform Party, a home for disenchanted independents. “The Republican Party has just moved too far to the extreme right,” he explained. “The Democrats are too far to the left.”
In the end, he dropped the campaign and the Reform Party, the leftover construct from Ross Perot’s two independent presidential candidacies during the 1990s. It was one of at least five times that Mr. Trump would switch party affiliations over the years. “I’m the Lone Ranger,” he once said in another context.
Now in the White House, President Trump demonstrated this past week that he still imagines himself a solitary cowboy as he abandoned Republican congressional leaders to forge a short-term fiscal deal with Democrats. Although elected as a Republican last year, Mr. Trump has shown in the nearly eight months in office that he is, in many ways, the first independent to hold the presidency since the advent of the current two-party system around the time of the Civil War.
In recent weeks, he has quarreled more with fellow Republicans than with the opposition, blasting congressional leaders on Twitter, ousting former party officials in his White House, embracing primary challenges to incumbent lawmakers who defied him and blaming Republican figures for not advancing his policy agenda. On Friday, he addressed discontent about his approach with a Twitter post that started, “Republicans, sorry,” as if he were not one of them, and said party leaders had a “death wish.”
While some conservatives complained about the apostasy of cutting deals with Senator Chuck Schumer of New York and Representative Nancy Pelosiof California, others applauded his assault on establishment Republican leaders like Speaker Paul D. Ryan of Wisconsin and Senator Mitch McConnell of Kentucky. By the week’s end, pundits speculated about whether Mr. Trump might seek re-election in 2020 as an independent.
“The truth is that he is a political independent, and he obviously won the nomination and the presidency by disrupting a lot of norms that Republicans had assumed about their own party and their own voters,” said Ben Domenech, publisher of The Federalist, a conservative website. “This week was the first time he struck out and did something completely at odds with what the Republican leadership and establishment would want him to do in this position.”
None of which means that Mr. Trump has suddenly transformed himself into a center-hugging moderate. More situational than ideological — critics would say opportunist — Mr. Trump adjusts to the moment, and his temporary alignment with Democrats could easily unravel tomorrow. The deal he cut, after all, merely postponed a fight over spending and debt for three months. It did not resolve any substantive disagreements.
But it showed that Mr. Trump does not feel beholden to his party. “I never viewed Trump as a strict adherent to Republicanism,” said Ned Ryun, a Trump supporter and founder of American Majority, which trains political activists. “He gave Paul Ryan and Mitch McConnell almost nine months to get something accomplished, and all they accomplished was to really remove all doubts about their legislative incompetence.”
Until now, the American two-party system has resisted assaults from the outside for more than a century and a half. No new party has captured the presidency since Abraham Lincoln’s Republicans in 1860.
Even formidable figures like Theodore Roosevelt failed to break up the duopoly. Unhappy with his Republican successor, William Howard Taft, Roosevelt formed his own Progressive Party, also known as the Bull Moose Party, to mount a comeback in 1912, winning 27 percent of the popular vote and 88 electoral votes, but losing to the Democrat, Woodrow Wilson.
Strom Thurmond in 1948 and George Wallace in 1968 staged independent candidacies founded on overtly racial appeals. John B. Anderson, a moderate Republican congressman, ran as an independent in 1980. The high-water mark since Roosevelt came in 1992, when Mr. Perot won 19 percent of the popular vote as an independent; he ran again in 1996 and drew less than half of that.
By running within the Republican Party, Mr. Trump last year managed what they never did, while making clear that he was not really a party man. The feeling was mutual. The Republican establishment resisted even after he had won enough primaries to secure the nomination, and he repeatedly threatened to run as an independent if he felt mistreated.
As someone who spent George W. Bush’s presidency as a registered Democrat, Mr. Trump had the potential to cross lines, but once inaugurated, he chose a hard-right path of banning visitors from certain Muslim-majority countries, pulling out of a climate change accord and seeking to overturn Mr. Obama’s health care program. He seemed uninterested in working with Democrats, and they seemed uninterested in working with him.
“There could have been some ways early on in his presidency to use his unique standing of a somewhat-independent who did not have the normal party strictures, and to date he has not been able to capitalize on that,” said Thomas F. McLarty III, who was Bill Clinton’s first White House chief of staff.
Yet even as he ignored Democrats, Mr. Trump was not governing as a traditional Republican, particularly on issues like free trade or national security alliances. Republican leaders distanced themselves when he made racially inflammatory comments after a white nationalist rally erupted into violence in Charlottesville, Va.
Other presidents have tacked against their own parties at times. Franklin D. Roosevelt sought to oust conservative Democrats who bucked him during party primaries in 1938. Ronald Reagan worked with Democrats, who controlled the House, to pass his agenda. Mr. Clinton introduced the term “triangulation” to the political vocabulary as he negotiated budget and welfare deals with Speaker Newt Gingrich.
But none seemed as distant from his own party as Mr. Trump. Breitbart News, the archconservative website run by his former adviser Stephen K. Bannon, delights in attacking establishment Republicans like Mr. Ryan. At a conference in Washington this past week featuring prominent political veterans from both parties, Republicans often expressed harsher assessments of Mr. Trump than Democrats did.
“There’s still a big question about whether he has a political strategy that matches his willingness to bash his own party,” said William J. Antholis, director of the University of Virginia’s Miller Center, which sponsored the conference. “There’s clearly a genius about Donald Trump. The question is whether it translates into political wins. If he continues to do this, would he get the Republican nomination? Would he run as an independent?”
The more immediate question is whether he will continue to seek agreements with Democrats. “President Trump campaigned as a conservative with an independent streak,” said Greg Mueller, a conservative consultant. “This disposition helped him build a winning coalition, but I think it’s too early to make a determination that he will now adhere to a strongly independent path and steer from his more conservative base.”
The Democrats’ liberal base finds Mr. Trump so anathema that party leaders will be pressured not to make concessions in the interest of finding consensus.
“The profound problem for him is this would have been a smart way to do things eight months ago, but post-Charlottesville, it’s really hard,” said Neera Tanden, president of the Center for American Progress, a left-leaning research organization. “He can do deals where Democrats win, but it’s really hard to get progressives to stretch for Trump.”
As for Republicans, Mr. Domenech said they should not think of Mr. Trump as their party leader. “They need to approach him the way they would have approached a Ross Perot presidency,” he said. “They’re dealing with a guy who technically has an R next to his name, but only technically. We have to convince him that our way is better, not just assume he’ll think so.”