After a primary season that has broken the rules and confounded the experts, Republicans and Democrats are now grappling with the same questions: What kind of candidate would Donald Trump be in a general election, and how should Hillary Clinton run against him?

At Trump headquarters, where the principal focus remains on securing the 1,237 delegates needed for the GOP nomination, officials are beginning to think seriously about the shape of the fall campaign. That includes the core issues of Trump’s message, the look and feel of the Republican convention this summer, electoral-map strategies, and what, if any, changes the New York billionaire might need to make — stylistically or otherwise — to expand his appeal.

Officials say two things are not likely to change. First, Trump would continue to be an outspoken candidate prepared to say unpopular or imprudent things. “What has been a certainty in this race is that Mr. Trump is going to be Mr. Trump,” said campaign manager Corey Lewandowski. “That is to say, his appeal has been as a person who tells it like it is.”

Second, officials say, Trump’s unpredictability — what critics regard as his lack of discipline — would prove to be an asset against Clinton, whom they regard as a far more conventional candidate. “Mr. Trump is a candidate who has the ability to change the narrative at any moment,” Lewandowski said. “Any other candidate would run a traditional campaign against Hillary Clinton.”

Clinton’s team and those at outside groups allied with her campaign are making similar assessments, looking for their own opportunities to expand the map into some traditionally Republican states while going to school on mistakes made by Trump’s rivals during the GOP primary contest. One big lesson is that his opponents waited too long to go after him and were timid when they did. Clinton and the Democrats probably would go early and hard against him.

Republican front-runner Donald Trump says he can't wait to take on Democratic front-runner Hillary Clinton in the fall, but here are three reasons why he could lose a general election. (Sarah Parnass/The Washington Post)

[Tense scene in California as demonstrators gather outside Trump event]

Clinton allies see Trump as a deeply flawed candidate — he has higher negative ratings than any past nominee in either party since polling began — with limited options to remake himself. They also doubt he wants to change his style.

“I’m not expecting a lot of Etch a Sketch with this guy,” said Geoff Garin, a Democratic pollster and an adviser to Priorities USA, a pro-Clinton super PAC. “Not that it wouldn’t be the right thing to do.” Garin was referring to the popular children’s toy that, with the shake of a hand, erases an image and offers a clean slate to create another.

As a result, Clinton’s team is preparing for what could be one of the nastiest campaigns in recent memory. “Hillary set out a year ago to be a champion for everyday people and to help families finally start getting ahead again in this economy,” said Robby Mook, Clinton’s campaign manager. “That’s what she’s going to keep talking about in the general election. . . . Trump, I’m sure, will try to bully and throw out insults. That’s not going to derail her.”

If some Republicans were hoping to see a more careful and judicious Trump as he moves toward the general election, they had to be disappointed last week when he attacked Clinton for playing “the woman’s card” and said that, if she were a man, “I don’t think she’d get 5 percent of the vote.”

To many strategists, that comment seemed like a classic mistake that would take away from an otherwise celebratory event after Trump’s sweep of five states. Instead, it could represent a template for the kind of campaign Trump runs this fall: one that is slashing, politically incorrect, ideologically inconsistent and designed to try to keep his opponent off balance. He could attempt to come at Clinton from both the right and the left.

Some current surveys, as well as electoral-map analyses, suggest that Trump would be an almost certain loser against Clinton and that his defeat would be sizable enough to take many other Republicans down with him. That’s the argument made by Sen. Ted Cruz (Tex.) and Ohio Gov. John Kasich, Trump’s last remaining opponents, as they try to stop him.

Other recent polls show the former secretary of state with only a narrow lead in a matchup against Trump, giving Republicans hope that once the two nominating conventions are over, fears of a Clinton presidency will drive many in their party to support Trump. Still, even Republicans who see strengths in Trump’s candidacy and admire the campaign he is waging for the nomination look toward the fall with great uncertainty.

“He has the biggest upside and the biggest downside of any candidate I’ve ever seen,” said former House speaker Newt Gingrich (Ga.). “If everything comes together and clicks, he’ll be a historic figure. And if everything goes sour, we’ll think of Goldwater and McGovern as medium-level disasters.” Gingrich was referring to Republican Barry Goldwater in 1964 and Democrat George McGovern in 1972, both of whom lost their presidential elections by landslides.

[Trump attacks Clinton for playing ‘the woman’s card’]

Some leading Republicans say privately that unless Trump makes changes in his approach before the general election, the party is destined to be outside the White House looking in for another four or eight years.

“Does he want to [change]?” a former Republican officeholder asked. “Does he think he has to? Or is he just as happy as he can be and doesn’t think he wants to change? If he is, he’s not going to win.” The official spoke on the condition of anonymity to talk candidly about Trump’s candidacy.

Paul Manafort, who was brought in recently as Trump’s convention manager with a broad portfolio, made news last month when he told members of the Republican National Committee meeting in Florida that Trump had been playing a “part” in seeking the nomination and would change as he looked to the fall campaign.

Trump has since made clear that whatever those changes are could be minimal. One bow to becoming the prospective nominee was to deliver a foreign policy address, using a teleprompter, last week at a Washington hotel. His advisers are hoping to develop better lines of communication — and relationships — with national and state party officials in preparation for the convention and the general election.

“It’s important to have a convention that focuses on introducing the candidate, believe it or not, and getting the message coordinated with the message of the party,” Manafort said. “Having a successful convention will also drive the negatives down and link the party to Donald Trump.”

Contrary to claims of Democrats, Manafort said he expects that Trump’s image will improve with time. “As he becomes the Republican nominee, there will be a consolidation behind him,” he said. “Once he is the nominee, some of that is going to come down naturally. . . . It’s a big deal when you’re the presumptive nominee as opposed to being the nominee.”

Trump’s rhetoric has sent those negative ratings skyrocketing, whether his attacks on Mexican immigrants, his proposal for a temporary ban on Muslims coming into the country or his call — later retracted — for penalties for women who have abortions.

His advisers see his rhetoric differently. They argue that, while he has said provocative things that have drawn condemnation or criticism, including that the United States should rethink its position in the North Atlantic Treaty Organization, over time some of his ideas have come to be seen as more acceptable or open to fair debate.

“He will not bow to being politically correct,” Manafort said. “His instincts of what the American people are thinking have been accurate.”

Mook, Clinton’s campaign manager, said: “I think they can try to remake or remodel him in any way his consultants might choose. But we have to take him at his word that he’s going to do everything he said he would do.”

[Indiana Gov. Mike Pence endorses Ted Cruz, praises Donald Trump]

Attacks, rather than contrasts on issues, are likely to animate the fall campaign, and here there’s no sign that Trump is ready to alter his approach. If anything, he appears eager to take on Clinton. “The notion that the negatives can’t change, or that we can’t improve or more importantly can’t increase Hillary’s negatives, is a fallacy,” Lewandowski said.

Gingrich said that on the basis of his reading of Trump’s record, the New York businessman has principles of action in which he truly believes. “These are not habits or personality quirks,” he said. “He always counterattacks ferociously. He also finds a way to define his opponent in a way that shrinks and limits them. These aren’t just barroom-brawl tactics. They are to define semantically his opponents in ways they can’t get out of — Hillary being the next great experiment.”

Dan Pfeiffer, former senior adviser to President Obama, said Trump presents a potentially unconventional target as a candidate. “I think his unpredictability challenges all the conventions of campaign strategy,” he said. “Everyone who’s ever run a campaign on the Clinton side has a playbook. They’ve never had to run against anyone like Trump. He confounded a lot of very good strategists on the Republican side, and he has the potential to do this here.”

That, however, doesn’t change Pfeiffer’s broader analysis: that Trump in the end cannot win the general election and that Clinton will be prepared to parry the attacks. “She has a lot of experience dealing with misogynistic males,” he said.

When asked about that Friday by CNN’s Jake Tapper, Clinton said, “I have a lot of experience dealing with men who sometimes get off the reservation in the way they behave or how they speak.”

Another Democratic strategist, who spoke on the condition of anonymity to offer thoughts about how Clinton could run against Trump, said the GOP candidate benefited immensely from the failure of his primary rivals to attack his weaknesses early enough or hard enough.

“They didn’t go after him,” the strategist said. “They didn’t stand up to him. . . . Nobody’s going to do that in a general election.”

Mook put it this way: “I think the election’s going to be incredibly competitive. It’s going to be close no matter what. The biggest risk that anyone can take on our side of the aisle is to assume that any part of this is going to be easy. It’s not.”

Lewandowski said Trump looks forward to drawing contrasts with Clinton on issues, from who can create jobs to their competing positions on trade; from a foreign policy that puts America first, rather than one that stresses nation-building, to a debate over the size and role of the U.S. military.

Manafort said: “Trump’s message is that he’s an outsider who owes nobody but the American people and that he will break the gridlock that has caused people to lose faith in Washington. That’s a message for the whole country. The message isn’t going to change. The audience is going to broaden out.”

Pfeiffer said there are aspects of Trump’s message that could appeal beyond the Republican base. “If you take out his positions on immigration and women, he has the most pure, economic-populist reform message. He’s got the best Republican message we’ve seen in a long time. Anti-trade, anti-Wall Street, anti-big-money-in-politics is very powerful.”

Garin agreed: “His economic message resonates with important parts of the electorate and makes it all the more important for Clinton to have a compelling economic message herself.” But, he added, “the economic message is a foundation that a candidate would have to build upon, and it’s not clear that Trump is ready, willing or able to put much on that foundation.”

The view from others with a stake in Clinton’s success is that there is enough else in Trump’s economic message to undercut those populist appeals, including a tax plan that would offer significant cuts to wealthy Americans. “He’s carrying the baggage of the Republican Party on his back. There is no evidence that he is offering anything that makes him more appealing than John McCain or Mitt Romney,” said one prominent strategist who is gaming out the fall campaign.

Yet at this stage, as Trump and Clinton try to close out their nomination contests and pivot toward what could be an epic campaign in the fall, the questions about Trump remain front and center.

Noting that Trump’s success fooled many people, Gingrich offered this final thought about what comes next: “Since none of us knew what was coming,” he said, “why do we now think we can project a Trump general-election campaign — including, by the way, Trump?”