President Trump is struggling to build a governing coalition that matches the nontraditional alliance that put him in the Oval Office. (Jabin Botsford/The Washington Post)

For a second consecutive weekend, President Trump remained in Washington — tweeting in the morning, holding meetings at the White House and heading to his Virginia golf club on Sunday — all the time surrounded by aides and patrons yet, increasingly, politically marooned.

Weighed down by dismal approval ratings, the president has been unable to wrangle enough support in Congress to advance his agenda and is searching for outside support to defend him from attacks coming from all sides.

Ahead of his 100th day in office, which he will mark this month, Trump has struggled to build a governing coalition that matches the nontraditional alliance that put him in the Oval Office. And he has turned to making enemies of former partners among Republicans in Congress, even as Democrats keep him at arm’s length.

“He seems both politically and personally isolated these days,” said David Gergen, a former adviser to Democratic and Republican presidents dating to Richard M. Nixon. “He’s flailing because he doesn’t know where to find his natural allies.”

The result has been a presidency lacking in significant victories, beset by major stumbles — including the downfall of the Republicans’ health-care bill and his travel ban on six Muslim-majority countries — and that is the target of litigation as a result of executive actions, especially related to the environment.

(Bastien Inzaurralde/The Washington Post)

There are more potential roadblocks ahead. Already, congressional Republicans have balked at his proposed budget, and the White House’s insistence on increased spending for the military and a wall along the U.S.-Mexico border could imperil a spending bill needed to keep the government running past the end of April.

No easy resolution has appeared, and despite loose talk from White House aides and staff-level conversations this week, little has been done to court Democratic support for his priorities. Meanwhile, most Democrats remain wary of Trump’s hard-line policies and incendiary persona, and the confirmation vote on Trump’s Supreme Court nominee, Neil Gorsuch, faces a potential filibuster by Senate Democrats.

“Part of it is self-imposed,” former Republican National Committee chairman Michael Steele said of Trump’s challenges and political drift, adding that many key players often find it difficult to build a bond with the 70-year-old executive. “People know him, they see him at meetings, but it’s been hard for people in Congress and around it to get to know him in a way that’s helpful for Trump.”

The White House last week resorted to threats against Democrats and members of its own party in an effort to push members to the negotiating table on repealing the Affordable Care Act and replacing it with the American Health Care Act, a Republican alternative championed by House Speaker Paul D. Ryan (R-Wis.) but beleaguered by opposition from conservative groups.

Weeks of early, politically damaging battles over controversial policies and an ongoing probe into his campaign’s ties to Russian interference in the election also have left Trump with the lowest approval rating of any president at this point in his administration since such data was first collected, during Harry S. Truman’s presidency. Most of the right-wing Republican House members in the Freedom Caucus, now in the president’s crosshairs, outperformed him in the 2016 election, giving them little incentive to cooperate.

“That’s what happens when you have an unpopular president . . . popularity scares people,” said Ari Fleischer a former adviser to President George W. Bush. “Lack of popularity emboldens them.”

The unrest extends to personnel and the Trump political operation. Last week, Deputy Chief of Staff Katie Walsh left the White House to help prop up an outside group that aims to provide air cover for the president in the legislative battles ahead after a health-care effort that left him exposed to criticism from the left and the right.

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In the West Wing, frustration abounds. For a president fixated on winning, people close to him say he is anxious to find out what went wrong with his team’s health-care push and get to a deal on that issue or another front such as taxes or infrastructure as fast as possible.

Christopher Ruddy, the Newsmax Media chief executive who is a friend of the president, said the lesson learned within the White House is to be more careful moving forward when it comes to trusting Congress and the leadership’s whip counts.

“The White House did the right thing. Ryan carried the luggage here. He delivered it and it was damaged goods,” Ruddy said of the health legislation. “They wanted to work with Congress, they accepted the congressional plan and it blew up on them. Now they realize they can’t do that in the future.”

Although the White House has not settled on a clear path forward, a partial strategy has taken shape on social media: going after the ideological purists who blocked Trump on health care. After dealing initially with the House Freedom Caucus with a carrot, Trump has settled on a stick, promising to “fight” Freedom Caucus members along with Democrats in 2018.

Among them: Rep. Mark Meadows (R-N.C.), a Trump supporter who defended him during one of the darkest periods of his campaign, when lewd “Access Hollywood” tapes emerged of Trump discussing grabbing women. Trump courted Meadows in meetings and calls, but White House aides say he feels scorned by Meadows and fellow Freedom Caucus members — and keeps a close watch on their television appearances and how they talk about him.

Some conservative leaders say the tensions between Trump and the Freedom Caucus could be fleeting because the president may eventually need them to pass legislation in the coming months.

“I think there’s a lot of frustration all around town,” said Michael Needham, chief executive of Heritage Action, which backed Freedom Caucus members in opposing the AHCA. “In a couple of weeks people will look back and people will say the coalition in the Republican House and the Senate is a center-right coalition that wants to get big things done.”

Trump showed some signs over the weekend of softening his assault on conservatives in Congress. On Sunday morning, he tweeted a more positive message about unity on health care — “Anybody (especially Fake News media) who thinks that Repeal & Replace of Obamacare is dead does not know the love and strength in R Party!” — and later went golfing with Sen. Rand Paul (R-Ky.), a staunch opponent of the bill who lobbied House conservatives to oppose it.

But building support will take more than schmoozing. Needham argued that the White House and congressional leadership asked Republicans to make a politically impossible decision on health care — casting a vote in support of a bill that had a 17 percent public approval rating, according to a recent Quinnipiac University poll.

That angst remains pervasive, with members wondering whether Trump is backing the right kind of bills, the sort of agenda that could lift him and the GOP ahead of the 2018 midterms.

Rep. Rod Blum (R-Iowa), a House Freedom Caucus member, said his office surveyed thousands of constituents about the health-care bill and found the response to be “overwhelmingly against it” — not just among Democrats, but independents and Republicans, too.

“I feel pressure, yes, I do: I feel pressure to say no,” he said. “They’re overwhelmingly, resoundingly saying, ‘Thank you for being a no.’ ”

As a candidate, Trump leapfrogged his opponents by running an anti-establishment outsider campaign. He pitched a populist infrastructure bill, tax code overhaul and a border wall — all of which have been held up by a push for a health-care bill that is more closely associated with long-standing Washington Republican dogma and that critics say fails to address Trump’s promise of making health care less expensive and more widely accessible.

Among Trump’s closest confidants are those urging him to abandon hard-liners in the Republican conference and strike a deal with Democrats on health care and on other issues.

“The president is a dealmaker, and he realizes that 30 members of the House shouldn’t control the process,” Ruddy said. “He is looking for a way to develop a majority that doesn’t include them.”

Striking such a deal is likely to require even more political acumen than bringing Republicans in line, as it could risk alienating the Republican leadership in Congress and the conservative base. It, too, would necessitate that Trump find stakeholders and power brokers he can trust on the other side of the aisle.

“You look at George W. Bush, who worked with Ted Kennedy early on with education. Trump is going to have to find somebody he can work with on the other side,” Rep. Peter T. King (R-N.Y.) said. “He knows he has to appeal to people because he’s not ideological, but he has to find out how he can get out of the Republican straitjacket and build the relationships, figure out a coalition for taxes, for infrastructure.”

Democrats remain skittish about cutting deals with a president who so easily lashes out at his own party.

“Right now he looks, I don’t know, in personal disarray,” House Minority Leader Nancy Pelosi (D-Calif.) said. “In some ways, he had a successful campaign, ‘Make America Great Again,’ something that is obviously very appealing to many people.

“He’s interpreting that as a personal endorsement,” she added. “Members of Congress vote their district; they don’t necessarily vote their president. The powers of persuasion that worked on the campaign trail aren’t going to seal the deal in Washington.”

Mike DeBonis contributed to this report.