Haley flopped. But she exposed Trump’s weaknesses on her way out.

Nikki Haley couldn’t stop Donald Trump. But by staying in the race through 25 contests, she gave Joe Biden and his allies a blueprint for where Trump is potentially weakest come November.

The former U.N. ambassador beat Trump in Vermont and Washington, D.C., and won more than 40 percent of the vote in New Hampshire and Utah. And though Haley’s appeal to Republicans in those places hardly dented Trump in the primary, the results suggest very specific vulnerabilities for the former president in the run-up to the general election.

A POLITICO analysis of primary voter data reveals that Trump struggled in places where a majority of adults are college-educated, including in key suburbs that doomed his campaign in 2020. And preliminary exit polling in North Carolina, Virginia and California on Tuesday showed more than two-thirds of Haley voters in each state weren’t committed to voting for the likely GOP nominee in November. Where Haley voters go — to Trump, Biden, another candidate or no candidate at all — could decide key races across the country.

“What [this] shows is a very strong trepidation about the [likely] nominee from the right demographics of constituencies,” said Mike Madrid, a Republican strategist and co-founder of the anti-Trump Lincoln Project.

“The base is not secure for Donald Trump,” Madrid said. And despite Biden’s deep unpopularity with much of the country, Madrid argued that the president “is in a much stronger position appealing to Republican base voters than he was four years ago.”

The scramble to do just that set in motion almost the minute Haley dropped out. Biden immediately issued a statement saying that there was “a place” for Haley supporters in his campaign. Trump said he welcomed Haley’s voters, too — but he also insulted her in the process.

And at least one outside group that worked to convince independents and Democrats to vote for Haley as a rebuke of Trump is now encouraging those same voters to cast ballots for Biden in November.

But anti-Trump forces face headwinds. Many of Haley’s voters are committed conservatives likely to favor the former president in the general election. Already, Trump has started locking up some of his most prominent Republican holdouts, including Senate Minority Leader Mitch McConnell.

Haley did not endorse Trump as she exited the race. And Trump will have work to do to earn the support of her voters, after he previously said anyone who donated to her campaign would be “permanently barred” from his MAGA movement.

Even as prominent Republicans quickly coalesced behind Trump, exit surveys showed Haley’s big appeal to voters in Virginia, North Carolina and South Carolina was as a vote against the former president.

The caveat is that more than half of Haley voters in Virginia and North Carolina also said they approve of Biden’s job performance, a metric that suggests she drew support from voters who backed Biden in 2020 — and who are likely to return to him in the general election. At the same time, that means that some of Haley’s strength might not mean Trump is losing voters — so much as she drew from a key part of Biden’s 2020 coalition that will be sticking with him.

Trump “will get some people back who are more Republican-oriented and find it hard to vote for a candidate who’s not a Republican. But I don’t think that is anywhere near the majority of her supporters,” said David Emery, a former Republican representative from Maine who had endorsed Haley and is now hoping for a “viable alternative” to Trump and Biden to emerge.

Emery believes up to 30 percent of Republicans are “just not open to any argument Donald Trump might make. Whether they vote for Joe Biden or sit it out, time will tell.”

Winning over so-called double-haters — voters who disapprove of both Biden and Trump — might not be an easy task for Democrats. Rep. Lisa Murkowski (R-Alaska), who had endorsed Haley, has said she “could not” vote for Trump or Biden this fall. Rep. Susan Collins (R-Maine), who voted for Haley, told NBC News on Wednesday that she is “not endorsing anyone.”

“Democrats did not do us a favor by putting in Joe Biden,” said Mary Small, a former Maine Senate Republican leader who co-chaired Haley’s leadership team there. “If they put in a moderate centrist, I’d be supporting a Democrat for the first time in my life. But I can’t support Biden.”

Still, anti-Trump operatives are picking apart primary voter patterns to see who can be convinced to vote for Biden in November. Primary Pivot, a super PAC that spent over $700,000 encouraging Democrats and independents in nine states to vote for Haley to protest Trump, has already rebranded in her absence as “Haley Voters For Biden.” Robert Schwartz, the group’s co-founder, said the PAC will now focus its outreach efforts in Michigan, North Carolina and Georgia heading into the general election.

Anyone looking to convert Haley voters has a pretty clear picture of where to start. The former U.N ambassador won just two dozen counties across all primary contests, although her best performances also tended to be in densely populated areas.

Those counties shared other key characteristics: In every single one of them, at least 40 percent of adults have a bachelor’s degree, a rate higher than the national average. Many of the counties represent exactly the kind of affluent suburbs that shifted heavily toward Democrats since 2016. In Virginia, for example, Albemarle County, which surrounds Charlottesville, swung 7 points towards Biden in 2020. Haley won it by more than 11 points on Tuesday.

Trump’s super PAC sought to frame overall GOP primary turnout as a rejection of Biden. "We anticipate a broad range of voters to turnout for President Trump's landslide victory in November,” said Alex Pfeiffer, communications director for MAGA Inc., the pro-Trump super PAC. And Republicans skeptical of Trump’s weaknesses have argued Haley’s best performances were largely a product of open primaries, where independent and even Democratic-leaning voters crossed over to vote against Trump. Some of those voters likely did boost Haley in states like Vermont.

But those independent and Democratic-leaning voters become more important in a general election — not less. And Trump’s weak performance in these suburban and highly educated counties spells trouble for him in November.

In Tennessee, where state law says only “bona fide” party members can vote in party primaries, Haley performed best in the Nashville area, clearing 30 percent of the vote in Davidson and Williamson counties, more than 10 points ahead of her statewide vote share.

Exit polls also showed other general election warning signs for Trump. In both North Carolina and Virginia, the former president’s support was weakest among women, whom he also struggled with in 2020.

Republicans need to win back those “independent moms, those suburban moms, those younger voters,” New Hampshire Gov. Chris Sununu, a prominent Republican critic of Trump who had backed Haley, told POLITICO ahead of her exit from the race.

“They’re just not going to do it with Trump as the standard-bearer,” he said.