ANAHEIM, Calif. — Orange County was the epicenter of the 2018 House Democratic takeover, where Republicans lost four seats in what was once the heart of Ronald Reagan conservatism in California. On Saturday night, as three of the victorious Democrats were honored at an annual political dinner, a new battle was on everyone’s minds: How to protect those gains in 2020 by selling voters on the impeachment inquiry of President Trump.
At the dinner, Representative Harley Rouda warned Democrats not to “sit on our laurels.” Representative Mike Levin solemnly said “the times have found us.” And Representative Gil Cisneros, who came out for the inquiry only last week, plugged his campaign website twice to ask for donations and noted, “The Republicans are coming after me now.”
A tricky balancing act is now underway for House Democrats as they return to their districts for a two-week recess that will double as a crucial time to frame a coast-to-coast debate over impeachment and the nation’s priorities.
Even as surveys showed more Americans embracing an impeachment investigation, voters talked mostly about issues like health care and the economy over the weekend at town hall meetings and party gatherings with House Democrats. Those members, especially in battleground districts, responded by highlighting their policy accomplishments and goals — while at the same time attempting to shape public opinion on impeachment and prepare voters for coming G.O.P. attacks.
That Democratic messaging challenge came into sharp relief during interviews with voters like Donna Artukovic, a retired teacher who was volunteering at the Orange County dinner. Ms. Artukovic expressed nervousness about what an impeachment battle could mean for Democratic candidates.
“I am afraid it’s going to hurt them,” she said. “A lot of people — even who don’t like Trump — don’t like impeachment.”
Representative Andy Kim of New Jersey, a Democrat who ousted a Republican incumbent in 2018 by focusing on issues like health insurance coverage for pre-existing conditions, held a town hall-style meeting in his district on Saturday where only one voter asked about impeachment (and even then, it was part of a multipronged question). In an interview afterward, Mr. Kim noted the paucity of questions on a topic that has engulfed Washington.
Referring to his constituents, he said: “They don’t want us to stop working on lower prescription drug costs and health care costs; they want us to move forward on infrastructure and jobs.”
As committed as he is on those goals, Mr. Kim said, he will also seek to draw on his experience as a former National Security Council member — which included sitting in on President Barack Obama’s calls to world leaders — to explain his views to voters on a matter like President Trump’s phone conversation this summer with the president of Ukraine.
“That’s hopefully what they’ll judge me on,” he said, “whether or not I was able to do this with a level of professionalism that’s distant from the partisanship they so badly despise.”
The House Democrats’ decision to undertake an impeachment investigation has already upended the presidential campaign, presenting both risks and opportunities to Mr. Trump and former Vice President Joseph R. Biden, whose son’s work for a Ukrainian gas company prompted Mr. Trump’s extraordinary intervention. But House Speaker Nancy Pelosi’s change of heart on impeachment, following months of reluctance to pursue an inquiry in the face of polls showing public resistance, has injected just as much uncertainty into the Democrats’ effort to retain the House.
It was new support for the impeachment inquiry from first-term lawmakers that steeled Ms. Pelosi to back the inquiry. But it is these same lawmakers who handed Democrats their 40-seat victory last year and who are taking a political leap of faith by backing the impeachment investigation.
The question that could determine their chances for re-election in 2020, and those of their Republican counterparts in both chambers who are defending the president, is whether the new evidence detailing Mr. Trump’s political overtures to Ukraine is enough to change public opinion of a president whose standing has been remarkably consistent despite his norm-breaking conduct.
The first independent polling since Democrats began the inquiry carries reassuring news for them — as well as some cautionary signs. A CBS News survey released Sunday indicated that 55 percent of Americans support an impeachment investigation, with Democrats now overwhelmingly supportive and independents about evenly divided. But only 42 percent of those surveyed said Mr. Trump deserved to be impeached, with 22 percent saying it was too soon to determine. This uncertainty is why House Democratic leaders are at pains to emphasize that they are not yet seeking to impeach Mr. Trump, but rather that they want to conduct a thorough investigation into his actions with the Ukranians.
“We’re not ready to call for an impeachment,” said Representative Cheri Bustos of Illinois, who chairs the House Democratic campaign committee and herself represents a district Mr. Trump carried. Ms. Bustos said the party’s message would be: “Let’s get to the truth.”
One reason she and other party leaders are acting carefully is the political standing of the remaining holdouts in the House Democratic caucus: Of the 12 members who have yet to call for even an inquiry, nine are freshman.
And some of these lawmakers, as well as colleagues from similarly competitive districts, are deeply uneasy about seeming too rash.
In a meeting before they left Washington last week, these vulnerable Democrats pressed Ms. Pelosi and her lieutenants to steer some of the more fervently pro-impeachment members of the House Judiciary Committee away from serving as the party’s on-air messengers for the inquiry, according to Democrats familiar with the conversation. And to give lawmakers a more substantive message to take home, Democratic leaders distributed packets on their next major piece of legislation, a prescription drugs pricing bill.
Representative Elissa Slotkin of Michigan, who represents a red-tinted district, said many voters needed time to make up their minds about impeachment and to understand the gravity of Mr. Trump’s call to Ukraine.
“I don’t think they’re there yet,” said Ms. Slotkin, another freshman, of her district’s voters. “Because there’s been a drip, drip, drip for months on this.”
In some of the more affluent districts that Democrats flipped last year, the first-term lawmakers have received reassurance in recent days that they are making the right decision. Mr. Rouda, Mr. Levin and Mr. Cisneros all said in separate interviews that the calls and emails that had come into their offices in the last week had been overwhelmingly in favor of pursuing impeachment.
And Representative Dean Phillips of Minnesota, who was the first freshman lawmaker to come out for the investigation last Monday, said that he received a number of calls from Republicans and independent voters who had pressed him to hold the president accountable.
Mr. Phillips’s fellow Minnesotan, Representative Tom Emmer, a Republican who chairs the party’s House campaign committee, said flatly that House Democrats’ impeachment march “will cost them their majority in 2020.”
Yet the most striking element of the CBS survey may have been the Republican movement on the matter: 23 percent of those surveyed said they supported an inquiry.
While that is a relatively small number, it is likely higher in the more upscale G.O.P. districts, such as the one Mr. Phillips represents outside Minneapolis, and it suggests there is an appetite for at least an examination of Mr. Trump’s actions.
That was apparent at a panel held in Austin, Tex., Saturday in conjunction with the Texas Tribune’s “TribFest.” While Representatives Jim Jordan of Ohio and Mark Meadows of North Carolina, two of Mr. Trump’s stoutest Republican allies in Congress, defended him, Representative Chip Roy of Texas said he wanted “to look at the facts.”
Some Republican strategists believe that the key for Mr. Trump is to make impeachment look like a partisan endeavor, with perceptions falling along the same lines of the country’s existing political polarization. The danger for him, then, is that any cracks among Republican lawmakers on impeachment could muddy this red-and-blue divide that often influences voters to side with their preferred parties.
If Republicans are not entirely united on the question of the investigation, Democrats are closing ranks.
Sarah Hunter, a retiree from Huntington Beach, Calif., said the Democrats she gathered with each day at her local dog park had gone from divided to united on the question.
“This latest thing is so egregious, it is so unbelievable that I do believe it’s time” to pursue an impeachment investigation, said Ms. Hunter, who attended Saturday’s party dinner here, where registered Democrats last month began outnumbering registered Republicans.
In addition to the new converts like Ms. Hunter, Democratic lawmakers have also been hearing from activists like Chris Simoes, a mail courier who attended Mr. Kim’s town hall Saturday on the Jersey Shore. Ms. Simoes said she called the lawmaker’s Washington office every day urging him to support impeachment after the transcript of Mr. Trump’s phone call with the Ukrainian president was released last week.
“I need Andy to get on board. What are you waiting for?” Ms. Simoes recounted saying. “I kept telling them the same thing: I know he’s in a tough district. I know because we all helped him get elected. It’s a tough decision. But this is a bridge too far.”
The most crucial voter bloc may be the increasingly small share of Americans in the political center. And that’s why Democrats are so determined to frame their actions as an inquiry rather than an impeachment.
“If this is a choice between investigating or stonewalling, a significant majority of independents will want to aggressively pursue this,” said Zac McCray, a Democratic pollster.
Mr. Levin, the California congressman, said that a survey he commissioned in July showed that voters in his district, which stretches from north of Richard Nixon’s old home in San Clemente south to La Jolla, were slightly more opposed to impeachment than supportive of it. But he suggested more of his constituents were likely on board now because of the stark facts of Mr. Trump’s actions with Ukraine.
“I explained them the other day to my 7-year-old son,” he said, “and I think he understood them.”
Jonathan Martin reported from Anaheim, Calif., and Catie Edmondson from Seaside Heights, N.J.