The Republican primaries are over and the general election has begun. Donald Trump will face off against Hillary Clinton to determine who will be the 45th president of the United States.

Trump reached presumptive nominee status on May 3, a month ahead of Clinton, giving him a head start to prepare. At the time, he faced two immediate challenges: unifying the GOP and building an effective campaign and fundraising operation.

So far both goals are works in progress. In some ways, it feels like the primaries never really ended. Trump is still clashing with high-profile members of his own party, who continue to criticize his inflammatory rhetoric and unconventional positions, and he’s still struggling to field a professional operation that can compete with Democrats.

These problems have prevented Trump from fully pivoting to an attack on Clinton, who launched her own broadside last week with a speech going after his temperament and foreign policy instincts.

“He missed opportunity after opportunity after opportunity to hit Hillary Clinton: on the [Inspector General e-mail report], on the jobs report, on her foreign policy speech. Completely missed it, “ MSNBC contributor Rick Tyler, a former Cruz spokesman, said in an interview with Thomas Roberts on Wednesday.

Trump will have a chance to refocus his campaign on Monday, when he will deliver what he’s described as a “major speech” laying out his case against Clinton. In a possible preview, Trump brought up her use of a private email as secretary of state in his election night speech on Tuesday, which he said was done to “keep her corrupt dealings out of the public record.” He also indicated he would delve into foreign donations to the Clinton Foundation, the global charity founded by the Clinton family, which he suggested were used to curry “favorable treatment.”

Related: Trump starts the general election after squandering head start

Trump is also working to address his fundraising operation, which has been sluggish getting off the ground, at a meeting with top donors in New York on Thursday. He largely self-financed his campaign in the primaries, which he said insulated him from special interests, but he will rely on donations in the general election. Trump acknowledged on Wednesday that he’s unlikely to match Clinton’s fundraising, which is expected to reach at least $1 billion with allied groups included.

“I just don’t think I need nearly as much money as other people need because I get so much publicity,” Trump told Bloomberg News on Wednesday. “I get so many invitations to be on television. I get so many interviews, if I want them.”

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Trump leans on these advantages. Republican operatives who went up against him in the primaries acknowledged Trump’s ability to dominate the news, rally his base and keep opponents off-balance with unpredictable attacks, even as they questioned his appeal to a general election audience.

“He is practicing asymmetrical war and Hillary Clinton is fighting a traditional trench warfare kind of campaign,” Terry Sullivan, a consultant at Firehouse Strategies who served as Marco Rubio’s campaign manager, told NBC News. “Anybody who says they know how it turns out is either lying to you or is clueless.”

The candidate faces major hurdles with key groups like Latino, black, and Asian voters, as well as white college-educated women, giving him little room for error even if he manages to boost margins and turnout among blue-collar white men, his strongest constituency.

Related: What took Donald Trump’s critics so long?

While there’s been a dearth of polls in the last week, Trump is competitive – or even leading – Clinton in several surveys taken in May. Surveys show Republicans consolidating behind his campaign and Clinton struggling to win over supporters of Democratic rival Bernie Sanders, who has yet to drop out of the race.

Republican pollster Chris Wilson, who worked on Senator Ted Cruz’s campaign, described Sanders holdouts as part of an “anti-Washington” vote on the left and right alike that could become a wild card in the election.

“There is enough of a white swing vote that’s been a traditional Democratic constituency for Trump to win,” Wilson said, adding that it could “shock us all” how effective Trump might be at drawing their vote.

In the meantime, Trump faces a Republican revolt of his own fiercer than anything he’s experienced since becoming the presumptive nominee in early May. Republican leaders, including Speaker Paul Ryan and Senate Majority Leader Mitch McConnell, have slammed him for his claim that a U.S.-born federal judge’s “Mexican heritage” influences his handling of a lawsuit alleging fraud at his Trump University program.

Trump’s meticulously delivered speech Tuesday, which included a rare use of Teleprompters, earned praise from some Republican leaders, but others on the right remained skeptical. Trump had delivered a similarly well-received election night address in April that many hailed as a sign of newfound maturity – only to fall back to his old ways two weeks later and falsely tie Senator Ted Cruz’s father to the John F. Kennedy assassination.

Unmoved by Trump’s brief display of discipline, conservative radio host Hugh Hewitt on Wednesday told listeners that Republicans should replace Trump at their convention or “get killed” in November. Cruz’s former co-chair Bob Vander Plaats, an influential social conservative activist, alsotold NBC News the idea was “on the table” and Wall Street Journal’s editorial board hinted Republicans should consider a convention coup as well.

Experts said the plot was highly unlikely to succeed – it would require delegates to drastically change convention rules and then a majority of delegates to coalesce an alternative – and influential delegates threw cold water on the idea. But that the idea was even raised is a remarkable sign of conservative angst over Trump’s candidacy.

Related: Republican Civil War Erupts Over Trump’s Attack on Judge

“I want to see a Republican in the White House,” Arizona Senator Jeff Flake, who has not yet endorsed Trump, told NBC News Wednesday. “But I can tell you, given the positions that Mr. Trump has taken so far, he’s not going to get there.”

This was hardly the first time that Republican lawmakers and commentators had revolted against Trump, however, and the previous blow-ups all ended the same way: with Republican voters still supporting Trump.

An online poll by YouGov on Wednesday that asked 1,000 adult respondents about the Curiel case suggested the dynamic may still be in effect. While 51 percent of all respondents called Trump’s comments about the judge’s heritage “racist,” a whopping 65 percent of Republicans disagreed.

The results echoed a similar outcry among Republican leaders over Trump’s call for an indefinite ban on Muslim travel to the United States, which state exit polls showed Republican voters strongly supported throughout the primaries.

Trump, for his part, seemed to take the latest criticism from GOP leaders in stride even as he told Timeon Wednesday he was “disappointed” by it.

"I’m a big boy," he said. "They have to say what they have to say."