John A. Boehner (R-Ohio) announced Friday that he would resign from Congress on Oct. 30 after nearly five years as House speaker. (AP)

The Republican Party came into 2015 in enviably good shape. Not since the Roaring Twenties had it elected so many members of Congress, and it had never controlled so many state legislatures. Its presidential field was the strongest in memory and the most racially diverse in history. Democrats, meanwhile, were led by a second-term president and his aging would-be successors.

Then came a topsy-turvy summer of presidential politics led by the unexpected popularity of Donald Trump. And rather than fading away as many predicted, the political climate has led to an even more tumultuous autumn: Just in the past week, onetime rising star Scott Walker dropped from the presidential race and House Speaker John A. Boehner (R-Ohio) stepped down. Both were undone by forces from within.

Boehner’s final act was an attempt to stop conservatives from triggering a shutdown fight over the defunding of Planned Parenthood. That has been put off, but only for now. Approval of the GOP-led Congress is in the teens, even among the Republicans who voted for it. People who have never won elections — billionaire Trump, retired neurosurgeon Ben Carson and former Hewlett-Packard chief executive Carly Fiorina — command higher support than the rest of the GOP presidential field put together and share an ability to force unwelcome topics into the news cycle.

All that is clear at this point is that the Republican Party is undergoing a volatile transformation. It is a party that knows what it doesn’t want far more than what it does. It has endured a years-long skin-shedding, beginning with the election of President Obama and growing even more intense at the end of his presidency, without having any idea what its next form will be.

The unrest was evident at this weekend’s Values Voter Summit, an annual gathering of social conservatives where, when Sen. Marco Rubio (R-Fla.) announced Boehner’s resignation, a ballroom’s worth of activists rumbled with applause. Trump mocked Boehner as a weakling that nobody really liked. Louisiana Gov. Bobby Jindal (R) called on Senate Majority Leader Mitch McConnell (R-Ky.) to follow Boehner out, for “the surrender caucus” to put down the gavels.

A crowd responded to presidential candidate Sen. Marco Rubio (R-Fla.) with applause after he announced House Speaker John A. Boehner’s resignation from Congress while speaking Friday at the Values Voter Summit in the District. (Family Research Council)

“That’s one down, that’s 434 more to go,” said Jindal, a former congressman. “Folks, it is time to fire everybody in D.C.”

Boehner’s departure was the third, and hardest, in a series of establishment body blows. The first was former Texas governor Rick Perry’s departure from the presidential race. Never a front-runner, Perry had studied hard after his 2012 implosion, and he had called Trump a “cancer on conservatism.” Voters didn’t heed him.

The second blow came when Walker, the governor of Wisconsin who had emerged as a tea party hero in 2010 after taking on that state’s public unions, ended his presidential campaign.

Neither man was an “insider,” and both disdained Washington. Neither could capture the anger of Republican voters.

“If the country were looking for a courageous, hard-working, relatively quiet person, you couldn’t do better than Scott Walker,” said Newt Gingrich, the former House speaker. “The minute he gets up and says, ‘I’ve won three elections,’ they say, ‘Next person.’ Trump changed the world. He ignited the legitimacy of being angry, noisy and aggressive.”

Boehner’s departure, the least messy of the three, was the most understandable. No one’s idea of a liberal, the congressman had started his speakership with a ban on earmarks. He had smothered all of the Democrats’ legislative goals, most notably immigration reform. Through committee appointments, he had turned House hearing rooms into murder boards for the Obama administration, not least after he created the Select Committee on Benghazi.

The problem was that the Republican Party’s conservative base had been promised more — sometimes by Boehner himself. The historic 2010 wins that gave him the gavel were powered by the tea party movement, which demanded the repeal of the Affordable Care Act and which Boehner indulged on the trail. In his first post-victory news conference, Boehner promised that Republicans would “do everything we can to try to repeal this bill and replace it with common-sense reforms.”

That never happened. Stand-alone repeal bills were smashed by the Senate. The debt limit, which conservatives attempted to turn into a vehicle for repeal, was passed with a smaller package of spending cuts. In 2013, those same conservatives were joined by Sen. Ted Cruz (R-Tex.) in a fight that briefly shut down the government, before it was reopened with full Obamacare funding. In 2014, conservatives won another landslide, and McConnell, the new Senate majority leader, seemed to suggest that they could finally unravel the Obama administration, “reducing the funding or restricting the funding” for bad law.

“What happens when he vetoes an appropriations bill,” McConnell told Time magazine, “is you re-pass it.”

Some minor tweaks later, the health-care law is intact, and few of the president’s executive actions have been undone. The conservative movement, from its media to its grass-roots groups, blamed anyone who had worked in Washington. In an NBC/Wall Street Journal poll released Friday, 72 percent of Republican voters said they were unsatisfied with their congressional leadership.

“Something that scares me, quite honestly more than this administration, is the inept, bloated, corrupt Republican Party led by the McCains, Romneys and — God forgive us — John Boehners of the world, who really have enabled this administration,” said Frank Bellistri, 66, who attended a town hall with Fiorina in Sandown, N.H., over Labor Day weekend. “As much as they go on their own they have enabled them, and it has really run roughshod on everyone in this room.”

The room burst into applause, and Fiorina was glad to chime in. “I worked hard to help elect a historic Republican majority in the House and to restore a Republican majority in the Senate,” she said. “And not a lot has changed. It is a leader’s job to produce results. And so I agree that the results have been thin and the results need to be coming, or we need different leadership.”

The parties have wandered into similar territory in other years, but they have never earned this sort of backlash. In 1999, a Republican Party that controlled Congress failed to achieve a conservative goal — removing Bill Clinton from office. Its base got behind George W. Bush, a Texas governor who talked about “compassionate conservatism” and compromise with Democrats. In 2007, a resurgent Democratic Party failed to cut funds for the war in Iraq, the issue that had won the midterms. Its primary voters split almost evenly between then-senators Hillary Rodham Clinton and Barack Obama, who had been there when the war was not just funded, but expanded.

“War is the hardest thing for the legislative branch to stop,” said Matt Schlapp, chairman of the American Conservative Union. “When it comes to Obamacare, it doesn’t make any civic sense to people that the courts and Congress can’t stop it. We picked conservatives for the court? They don’t act like conservatives. We elect conservatives to Congress? They can’t stop Obama.”

Today’s Republican base has not been so easily mollified. The groups that had thrived during the tea party’s heyday universally celebrated Boehner’s resignation Friday, accusing him of weak leadership that enabled the Obama presidency.

“Rather than fighting President Obama and his liberal policies, Speaker Boehner embraced them and betrayed his party’s own voters,” said Ken Cuccinelli II, the former attorney general of Virginia who runs the Senate Conservatives Fund.

“For five years, Speaker Boehner has heard loud and clear from the people who gave him a Republican majority that they wanted conservative leadership,” said onetime Tea Party Patriots leader Mark Meckler. “For five years, he has practiced surrender, capitulation and compromise of conservative principles.”

Many Republicans in office owe their jobs to that sentiment. In some states, where Republicans control every level of government, the anger can be directed. Nationally, it’s uncontrollable. The louder the attack on the president, the more the base wants to hear.

“This is why outsiders are all leading in the polls,” said Gov. Sam Brownback (R-Kan.), a former congressman who served alongside Boehner.“This is probably a key part of why Boehner’s resigning. They don’t want to hear any excuses anymore — they’re done with that. If you say you tried, they ask, ‘Why didn’t you get it done?’ ”

Echoing Boehner, some Republicans say that a polarized media and political debate have left voters confused. “When I go home and I tell people what we’ve done, they have no idea,” said Rep. Frank Guinta (R-N.H.). “There’s not a lot of attention paid to what the House of Representatives has accomplished. People get their media in very different ways now. They feel that there’s inaction in Washington.”

Those same voters are gravitating to the outsiders, who assure them that they’re right — that Washington is beyond saving. In a current average of New Hampshire polls, Fiorina has surged into third place, behind only Trump and Carson.

Robert Costa and Jenna Johnson contributed to this report.