We head into the first presidential debate in Cleveland with Donald Trump leading the field and confounding the confident predictions of a slew of pundits that his collapse was at hand—whether after the Mexican-rapists comment, the slam at John McCain as no hero, or other statements that offended elites but only seemed to attract more support from Republican hoi polloi. What explains the Trump bump? The answer is the emerging, even dominant force in the GOP—an angry, anti-establishment, anti-leadership populism that was triggered by the financial crisis and the 2008 bailout, cynically exploited in 2010 and 2012 by the “Young Guns” in the House and other GOP leaders in Congress to convert anger into turnout and elect Tea Party-oriented candidates. This force is now turning on those leaders, creating problems not just in the presidential race, but in a Congress whose leaders face the possibility of implosion ahead.

The angry populism has only grown with conservative rank and file incited to expect the repeal of Obamacare and an Obama capitulation on debt-ceiling showdowns and government shutdowns, ending repeatedly in disappointment. The sharp drop in Republican Party favorability shown in a recent Pew survey was driven by disenchantment among Republicans—an 18 percent decline in only six months.

Trump has become the lead channel for angry populists. But following behind is Ted Cruz, who rode the wave to his Senate election—beating, in a primary, a bedrock conservative who had the misfortune of being an office holder—and then to his role as a thorn in the side of his own party’s establishment. Cruz upped the ante last week with the unprecedented step of calling Senate Majority Leader Mitch McConnell a liar on the Senate floor as McConnell maneuvered to assuage most of his conference and the business community by securing a vote to salvage the Export-Import Bank. And, the same week, another angry populist, House Republican Mark Meadows, dropped a resolution to remove the Speaker. Two shots across the bows of the top-Republican leaders in Congress both Boehner and McConnell—conservative by any objective standard, but neither conservative or radical enough to satisfy the large and restless populist wing of the party.

The dysfunction of the majority in Congress was predictable (and predicted). After Republicans won the Senate and gained seats in the House in the 2014 midterms, a parade of leaders from Speaker John Boehner and House Majority Leader Kevin McCarthy to McConnell and his deputy John Cornyn said that Republicans were now going to have to share responsibility for governing—meaning no shutdowns, no more fandangos over the debt ceiling, and a positive agenda to send bills reflecting a conservative framework to the president for signature or veto. That included an alternative to Obamacare and action on pressing problems like infrastructure.

But those high expectations were going to come up against the underlying differences in outlook, rules, and electoral dynamics between the two chambers. The Senate worm turns from 2014 when a slew of vulnerable Democrats elected in 2008 were up, to 2016, with many more Republicans up than Democrats, including several elected in the great GOP sweep in 2010 from blue states. The result required McConnell to shape votes and issues to protect them, but with no comparable group among House Republicans. That fact alone meant that most bills that could capture majorities in the Senate would not be acceptable to Republicans in the House, and vice versa. In the House, there is the unusual challenge, especially for Boehner, of finding majorities with Republicans alone. That challenge was itself underscored at the beginning of the new Congress when, despite the excellent election results, 25 Republicans voted against Boehner for Speaker—the largest number of defectors in a century.

The first eight months of the 114th Congress were characterized far more by failure to launch than by policy accomplishments. And the dysfunctional interaction between the angry populist, radical wing of the GOP and its more pragmatic establishment leadership showed itself, especially as the dozen spending bills needed to fund most of government beginning October 1 began to emerge in the House.

The Interior bill came out of the Appropriations Committee on a sharply partisan basis, fracturing decades of tradition of bipartisan cooperation on the panel. This bill cut spending in popular areas sharply, but even more controversially added riders to curtail executive authority in areas like public lands and the environment—ensuring no Democratic votes for the bill on the House floor. But garnering a majority from Republicans alone means finding ways to capture the share of the conference who do not want to vote for any bill that involves government spending. In this case, the effort to capture that group meant offering Southern conservatives a vote on allowing Confederate flags on public property—the same week as the deeply emotional funeral services in Charleston, and a huge embarrassment for Republican House leaders. The bill was pulled and has not reemerged—nor have other appropriations bills as the clock ticks before the new fiscal year begins. And, of course, even if the bills make it through the House, they have to do the same in the Senate, and be reconciled, all by September 30. Now, there is the added complication, the growing, vociferous demand, to blow up funding for Planned Parenthood, with Cruz among others demanding a shutdown, if necessary, to accomplish that goal.

The leaders’ solution to avoid a shutdown is to punt—a continuing resolution for most or all of the spending bills, ostensibly for just a few weeks. But there is no reason to believe that the dilemma they face will ease in October or November. That leaves two alternatives. The first would be a grand bargain, like the one achieved in 2013 by Paul Ryan and Patty Murray, that would effectively ameliorate the sequester cuts for both defense and domestic programs, and probably continue significant funding, perhaps with some modifying language, for Planned Parenthood. The second option would be passing a continuing resolution for much or all of the fiscal year. But the former, by reducing the sequester, would be seen as a sellout by a swatch of Tea Party lawmakers. And the latter would mean spending continued at the previous year’s levels.

For Tea Party conservatives, the sequester cuts, draconian as they would be for domestic programs across the board, were not enough to begin with. A continuing resolution wipes those out, meaning total defeat on the cutting-spending front. All perpetrated by their own leaders! And, in the House, passing either a grand bargain or a continuing resolution almost certainly will happen with far more Democrats supporting it than Republicans, adding to the rage angry-populist members feel toward their Speaker.

Remember, all of this will play out in October just as the presidential nominating process is really heating up. As it unfolds, expect the slew of angry-populist presidential candidates, some of them sitting senators, including Trump, Cruz, Mike Huckabee, Rick Santorum, Ben Carson, Carly Fiorina, and others, to push Congress to toughen up, stare Obama and his Democrats down, and push for confrontation. They will do the same, most likely, with the debt ceiling, which has to be raised by November or December, putting additional pressure on McConnell, Boehner et al. And they will join the chorus, raising bloody hell as the primaries and caucuses begin about the perfidy of their own establishment leaders, getting even more distance from a Washington where Congress is run by Republicans.

Two intersecting roads explain a lot about today’s American politics. One, of course, is Pennsylvania Avenue, running from the Capitol to the White House. The other is the long and winding road to a party’s presidential nomination. The last week or so has demonstrated that the intersections can lead to collisions. Brace yourselves for more to come.