WASHINGTON - Donald Trump will be the next president.

Now what?

Local members of Congress - the representatives who will be on the front lines of enacting or obstructing Trump's vision - are readying for a new era under a president whose policy promises were vague and whose election sent tremors through many.

In the days after the bitter campaign ended, Democrats groped for a way forward and empowered Republicans began looking toward governing.

One battle has already come into focus, one that could offer a glimpse of the political strategies and postures that could shape the new president's first term.

Trump and top Republicans have pledged to repeal the Affordable Care Act, a move that would affect about 20 million people receiving health coverage through the law, President Obama's signature initiative.

Trump can take some unilateral action to chip away at "Obamacare," and Republicans can push bills through the House without Democratic support. But Democrats have enough Senate votes to use a filibuster to block legislation there.

And they have vowed to fight.

"I will do anything I can to prevent going back to the day when if you had a preexisting condition, you couldn't get health insurance," said Sen. Cory Booker (D., N.J.).

Consumer protections - such as allowing young adults to stay on their parents' insurance and requiring insurers to offer coverage regardless of a person's medical history - have helped 150 million people, said Sen. Bob Casey (D., Pa.), a fact Democrats pledged to highlight in the face of any repeal vote.

"Under the old way, if a woman was pregnant, that was a preexisting condition," Casey said. "Are we going to go back to those horrific dark days where insurance companies controlled your life?"

He said Democrats would force Republicans to explain "what is your replacement?"

Even Republicans who oppose the law favor some provisions, such as the ones Casey cited. Trump indicated to the Wall Street Journal on Friday that the protections for people with preexisting conditions may remain intact.

Rep. Ryan Costello, a Republican from Chester County, said no one will be suddenly kicked off their health plans. It could take years to roll back Obama's law and move to a new system. But he said changes would have come no matter who won the election, because of sharply rising costs.

"Everybody who has health coverage should be able to stay on that coverage, and, to me, the issue isn't about reducing coverage," Costello said. "The issue is going to be about reducing cost."

Sen. Pat Toomey (R., Pa.) urged a move to a system "driven by consumers."

In other areas, though - including trade and federal entitlements - Trump's populist promises break from congressional Republicans' business-friendly platform. He supports new funding for infrastructure, something Democrats have long favored but that conservatives have resisted, citing the potential price tag.

"If Donald Trump happens to agree with our position, which he says he does, then we would be happy to work together on that," said Rep. Brendan Boyle, a Democrat whose district includes parts of Philadelphia and Montgomery County.

Aside from policy questions, both parties will be left to grapple with the fallout from an election marked by resentment.

Many elected officials - including some Republicans - recoiled at Trump rhetoric that seized on and sometimes seemed to encourage racial animus and misogyny.

"If he tries to govern the way he campaigned, he will be a colossal failure as a president," Booker said.

While congratulating Trump in a Facebook post, New Jersey's Robert Menendez, the only Latino Democrat in the Senate, said he "can never forget what he has said about Hispanic Americans."

"The president-elect has an opportunity to show the community that his actions are different than his words," Menendez wrote in a message posted in English and Spanish.

Casey cited reports of racially charged harassment and intimidation in the days after the election, saying Trump has an obligation to speak out against such behavior.

"Presidents aren't just policy machines," he said. "Presidents have to lead and demonstrate that they're going to lead with moral authority, and if they don't, we should criticize them aggressively."

Trump's tone may have cost him in Chester County, where he lost to Hillary Clinton on the typically Republican turf by 25,000 votes.

"There are people who are very anxious, there are people who are very excited, there are people who don't know what to think, and then there are people who are very fearful," said Costello, whose district includes much of the county.

But he noted that those emotions would have still existed - only flip-flopped - if Clinton had won.

Just days after the election, members of both parties remained unclear about what other plans might come from a president-elect whose policies could change as quickly as his mood.

The uncertainty is evident: Several local lawmakers, including Republicans who had opposed Trump, declined or didn't respond to requests for interviews.

"Let's be honest: This was a campaign about personalities and about frustrations. I don't believe it was about specific policy proposals from either side," Costello said.

He said he hoped that the House could be an "engine" of ideas, including tax reform and other steps Republicans say will spur economic growth.

Democrats, meanwhile, face internal questions about how to relate to the working-class voters who rejected Clinton.

"The Democratic Party's economic agenda is overwhelmingly in those voters' economic interest," said Boyle, who grew up in a blue-collar family in Northeast Philadelphia. "For too long our party has not focused enough on reaching out to blue-collar voters in Northeast Philly, Scranton, rural America, and in this election, it ended up costing us."

With anti-Trump protests erupting in some cities, members of both parties urged unity.

"The last time I looked, Donald Trump was the president of the United States of America and we're all Americans - he's my president now," said Rep. Robert Brady, the Philadelphia Democrat who represents one of the country's most Democratic districts.

Toomey declined to back Trump until late on Election Day. But after he and the GOP presidential nominee won hard-fought races, the senator said it was time "to pull together and look for common ground."

@JonathanTamari

Staff writer Justine McDaniel contributed to this article.