The powerful and well-funded conservative movement has launched into overdrive to rescue the Supreme Court nomination of Brett M. Kavanaugh, decrying the sexual assault allegations against him as unfounded and warning Republicans that buckling to Democratic pressure would undermine voter enthusiasm weeks before the midterm elections.

The increasingly charged fight with Kavanaugh’s accusers and Democrats has already gone far in harnessing Republican rage over shared grievances and has united conservative factions at a critical juncture in Trump’s presidency.

“It’s jazzed them up to the point they’re disgusted and they’re paying attention,” said Rep. Steve King (R-Iowa), a conservative hard-liner who is close to activists. “It’s in the soul and the bones of the movement to make sure the Supreme Court doesn’t turn our society hard to the left.”

Rather than tread cautiously amid sensitive allegations and the #MeToo movement, conservative forces have instead grown aggressive in recent days — speaking darkly of a Democratic smear campaign and attacking the credibility of Kavanaugh’s accusers across media platforms and social-media channels.

And the stakes are being framed in near-apocalyptic terms, aimed at injecting a new sense of urgency into a challenging year dominated by an energized Democratic electorate and the rise of the anti-Trump resistance.

“If the Republicans do not get this vote taken and have Kavanaugh confirmed, you can kiss the midterms goodbye,” influential conservative talk-radio host Rush Limbaugh told his listeners this week. That message was amplified Tuesday by Trump, who posted Limbaugh’s remarks on Twitter.

Some GOP voters who months ago agreed with Trump’s prediction of a “red wave” of Republican victories this fall, even as a polls showed Democrats positioned to win back the House majority, are now alarmed.

“They need to just get him confirmed and moved through,” said George Bowles, a 62-year-old Republican in Florida’s Brevard County, which Trump carried by nearly 20 points in 2016.

Bowles also dismissed the allegations against Kavanaugh as a witch hunt against an innocent man: “This is just stupid, stupid, stupid . . . I can’t remember what I was doing 35 years ago. Can you?”

Christine Blasey Ford told The Washington Post last week that Kavanaugh sexually assaulted her at a party in the early 1980s when they were both teenagers. Kavanaugh has strenuously denied Ford’s accusation and that of a second woman, Deborah Ramirez, who alleged in an article in the New Yorker on Sunday that he exposed himself at a party while the two were freshmen at Yale University.

Republican leaders, seizing on the outpouring of conservative anger as Kavanaugh has faced scrutiny, have stood by the federal judge and largely moved on from their sense of distress last week about the political cost with women and independent voters. They are focused on stoking their base voters, some of whom have become frustrated over the past year with Trump’s failure to eviscerate President Barack Obama’s health-care law and secure funding for a massive wall along the U.S.-Mexico border.

When a Republican operative tweeted this week that “this clown show from the Democrats and their media cohorts is enraging,” Josh Holmes, a top adviser to Senate Majority Leader Mitch McConnell (R-Ky.), agreed and said the reaction has upended the year’s political dynamics.

“I’m hearing a LOT of this from Republicans across the country who have by and large taken the cycle off until this point,” Holmes responded on Twitter.

Optimism about a suddenly galvanized Republican base and conservative movement was shared by GOP lawmakers on Tuesday.

“They think the Democrats are just out to get Trump, no matter what. They’re trying to destroy Kavanaugh,” said Sen. Lindsey O. Graham (R-S.C.). “It looks more like a piling-on here. It’s going to blow up in the Democrats’ face.”

“Most of my constituents believe that these allegations are late — either late, irrelevant or untrue,” said Sen. John Neely Kennedy (R-La.).

McConnell told reporters that he is “moving forward” with the nomination and is “confident we’re going to win,” although several moderate Republicans such as Sen. Lisa Murkowski (R-Alaska) have not announced a final decision on their vote.

For Democrats, the Republican push against Kavanaugh’s accusers has been seen as an opportunity to underscore their own party’s connection with the #MeToo movement and women nationally.

Across the country, a wave of protests have been held with speakers expressing solidarity with Kavanaugh’s accusers and calling for an FBI investigation into the allegations, which Republicans have refused to request.

“Leader McConnell owes an apology to [Ford] for labeling her allegations a smear job,” Senate Minority Leader Charles E. Schumer (D-N.Y.) said Tuesday.

Meanwhile, conservatives are working to ensure McConnell’s prediction comes true and that conservatives remain engaged. Vice President Pence and McConnell, among a crowd of other Republican luminaries, rallied activists over the weekend at the Values Voter Summit in Washington, and online, conservatives are blanketing their favored outlets with pro-Kavanaugh material.

White House counsel Donald McGahn, a movement veteran, has been bunkered with Kavanaugh in prep sessions for Thursday’s scheduled Senate hearing about the allegations, while a right-wing public-relations firm is operating a response operation akin to a war room in suburban Virginia.

But conservatives have also had to grapple with a botched conspiracy theory pushed by a prominent conservative lawyer that undermined their arguments. Ed Whelan took a leave of absence this week from his position as president of the Ethics and Public Policy Center in the wake of tweets, since deleted, suggesting that Kavanaugh’s accuser may have mistaken the jurist for someone else — and naming a former Kavanaugh classmate as a likely suspect. Days earlier, Republican senators were widely criticized for dismissively referring to Ford as a “lady” who may be “mistaken.”

The political machine on the right has kept humming throughout the fallout. Conservative groups have spent millions to boost Kavanaugh, including more than $7 million in advertising and grass-roots activity by the Judicial Crisis Network, a group that does not disclose its donors.

That organization and other entrenched movement groups like it began planning for a protracted fight months before the Supreme Court’s perennial swing justice, Anthony M. Kennedy, retired this summer.

Gary Marx, a senior adviser to the Judicial Crisis Network who manages daily conference calls with conservative allies, said the hurdles facing Kavanaugh have brought together key conservatives following months of tensions and controversies within the Republican Party.

“This is a pivot point in our nation’s politics and culture, and we’re all now back in the foxhole together,” Marx said. “This has pushed all of it back to where we were in the closing days of the 2016 campaign when even the senators and the conservatives who didn’t like Trump decided to back him because they knew he’d be able to change things like the Supreme Court.”

Adding to the angst, however, is Trump’s sometimes fragile relationship with the conservative movement that helped lift him to the White House.

While Trump has largely aligned himself with conservatives’ priorities and taken McGahn’s advice on the courts, there is growing concern that Kavanaugh’s troubles could test the strength of that bond, according to associates of the president.

“The president likes Don, and he knows he needs [the conservative movement] with him. But his base isn’t only the people in the Federalist Society,” a conservative legal group, said one Trump confidant, who requested anonymity because they were not authorized to speak publicly. “It’s bigger than that, and he’ll always do what’s best for him.”

Still, most Republicans believe that Trump, too, has been jolted by Kavanaugh’s struggle as much as any GOP voter. Some pointed to his derogatory comment on Tuesday claiming Ramirez “has nothing” and was “totally inebriated” the time of the alleged incident as being in step with conservative opinion, both among the establishment and the base.

“It’s just a game to them, but it’s a very dangerous game for our country,” Trump told reporters in New York. “They know it’s a con game, and they are winking at each other.”

Tim Craig, Seung Min Kim and Mike DeBonis contributed to this report.