“The Wall” began as just a slogan. By the end of the 2016 presidential campaign, it was Donald Trump’s signature promise, a metaphor for his entire domestic agenda as well as an actionable item in its own right. Which makes it remarkable that, nearly two years into his administration, “The Wall” is on life support.

Democrats, invigorated by their midterms victory and confident of their political position, refuse to authorize funding for Trump’s priority. And Republicans, demoralized by their defeat, are indifferent, doing little to advance his agenda. A stronger president might have leverage to wield over his allies or his opponents, but a floundering Trump has only one option available—the self-destructive threat of a government shutdown.

The spectacle of Trump holding himself hostage to achieve one of his goals is a darkly comic example of a vital but still underappreciated fact of American politics: The president and his administration are exceptionally weak. This assessment isn’t just based on the results of the midterms; Donald Trump has diminishing status and influence within the Republican Party itself. This may feel counterintuitive given Trump’s continued high standing with Republican voters: According to the latest Gallup weekly average, 86 percent of self-identified Republicans approve of his job performance. Likewise, in a recent poll from NBC News and the Wall Street Journal, 57 percent of GOP voters say they identify as Trump supporters more than members of the Republican Party. At the same time, presidential strength is as much about the executive’s ability to work his will—to move people, personnel, and policy—as it is about performance in public opinion. Trump is popular with Republican voters, yes, but that’s just one element among many.

His presidency is stalling out—if it hasn’t stalled already—with even more scandal and chaos on the horizon as a Democratic House majority flexes its oversight powers.

Consider just the past two months: Not only did Trump lead his party to a historic midterms defeat, but his already chaotic White House devolved further with the firing of Attorney General Jeff Sessions, the impending departure of White House chief of staff John Kelly, and the resignation of Interior Secretary Ryan Zinke, who—like several of his peers in the administration—is plagued by scandal and allegations of corruption.

Kelly’s departure is especially significant. The chief of staff role is one of the most powerful (and coveted) in government, and yet, Trump has not been able to find a suitably high-profile replacement for Kelly. His first choice, Vice President Mike Pence’s chief of staff, Nick Ayers, publicly rejected the job, as did possible candidates like former New Jersey Gov. Chris Christie. You can chalk this up to reluctance to dive into the chaos of the Trump White House, but it also reflects real distance between Trump and the GOP establishment. A stronger, more capable president could rely on party ties and networks to find the right candidate if the need to refill the position arose. Trump, by contrast, has been rejected by nearly everyone with ties to the institutional Republican Party. The relationship is strained.

That strained relationship also helps explain why at least one Republican hasn’t dismissed the idea of a 2020 primary against Trump. “I see nothing wrong with challengers—that is part of our democratic system,” said Sen. Susan Collins of Maine on CNN’s State of the Union on Sunday. “It’s healthy for our democracy.” It’s not that a primary is likely, or that it would succeed. But It’s unusual for a co-partisan to entertain the idea. Collins may back the president’s judges and dismiss accusations of his criminality, but she seems aware that he is vulnerable. South Carolina Republicans have even mulled canceling the state’s 2020 presidential primary, a move that seems designed to protect Trump from any primary challengers. State GOP Chairman Drew McKissick insists that “the entire party supports the president”—but canceling a primary is the move you take if you’re not so sure he would withstand a challenge.

Trump’s position is only getting weaker. On Tuesday, former national security adviser Michael Flynn appeared before a federal judge to receive a sentence for lying to the FBI during its investigation into the president’s campaign. Trump is shutting down his foundation, following allegations of “persistently illegal conduct” from the New York attorney general’s office. As the initial lawsuit said, “the Foundation was little more than a checkbook for payments to not-for-profits from Mr. Trump or the Trump Organization.” Trump has also ended up surrendering in negotiations for government funding, retreating from his demand for “wall” funding. His signature policy is dead, if it ever was alive in the first place.

Having said that, GOP lawmakers are still covering for the president. Confronted with court filings directly implicating Trump in plans to silence women who might level public accusations against him, in violation of campaign finance law, Senate Republicans shrugged. “I mean, until we know all the details—it’s a sentencing filing,” said John Thune of South Dakota. “I’m sure there’s going to be a lot more [to] come out from the Southern District (of New York) and, at some point, from the Mueller investigation as well. So, it’s hard to read too much into it.” Likewise, said Roy Blunt of Missouri, “I don’t know that it changes things much. … I think you would have to have more than this happen before anything changes much.” But this lack of interest may actually underscore the president’s weakness: To acknowledge federal allegations against the president would only serve to further destabilize his administration, a move that would damage Senate Republicans along with Trump. Better to avoid the question than to pile on, especially with the president’s poor standing with independent voters, who broke for Democrats in the midterm elections.

Donald Trump is still full of bluster. He can still count on the support of Republican voters, and he will likely still receive support from many Republican lawmakers. But his presidency is stalling out—if it hasn’t stalled already—with even more scandal and chaos on the horizon as a Democratic House majority flexes its oversight powers. And while it’s too much and too soon to predict a complete break between Trump and the GOP, the extent to which Republicans are distancing themselves from the White House is a poor sign for a future where even more of the administration is under investigation. The party, or at least a faction of it, is taking a “wait and see” attitude to Trump. And you don’t need a cascade of defectors to deal a major blow.

The signs of a collapse are here. The question is what pushes everything over the brink.