WASHINGTON – Republican Rep. Erik Paulsen's Third Congressional District is solid Marco Rubio territory.

The party faithful in Paulsen's district overwhelmingly chose the Florida senator over Donald Trump and Texas Sen. Ted Cruz in precinct caucuses March 1.

But Trump's surging candidacy nationally is causing fresh angst in many GOP congressional districts as the sometimes brash billionaire's rhetoric risks alienating the kind of affluent conservative suburban voters that Paulsen has relied on for years. Trump's wave of new momentum — and passionate GOP detractors — is suddenly throwing usually reliable seats like Paulsen's into the tossup category.

Paulsen, who endorsed Rubio in late February, said he expects to support the party's eventual nominee — even if that is Trump. While Paulsen worries about the intense Republican criticism surrounding the GOP front-runner, he said he understands the frustration expressed by Trump supporters in his district.

"I really do believe Washington is broken," said Paulsen, who has served in Congress since 2009. "I think after the elections happened in the past, nothing changes, and that's where the frustration is coming from, that's what's built up the movement."

But when pressed, Paulsen declined to say how he reconciles some of Trump's more inflammatory positions, like banning Muslims from the United States and deporting all undocumented immigrants. Some of Trump's most heated rhetoric runs against Paulsen's own statements on immigration reform, which he has said would improve the economy.

"I'm supporting Rubio and expect him to be the nominee," Paulsen said.

Worry in the party

Paulsen's more conciliatory tone is a sharp contrast from many influential Republicans, who see Trump's breakaway momentum as nothing short of disastrous for the party.

Worry about a Trump candidacy dragging down GOP turnout has shaken House Republicans nationally. Many prominent members of the party — including former Minnesota Sen. Norm Coleman — have said they will not support Trump if he is the nominee. Greg Walden, chairman of the committee in charge of keeping the GOP House majority, said at recent media events that a Trump ticket jeopardizes competitive congressional seats.

Paulsen, who has a reliably conservative voting record but a mild-mannered message of lowering taxes and cracking trade wide open, has cut a low-key political path in an area where Trump's caucus support was weak. Paulsen's district tilts GOP, but President Obama won it twice, as has Democratic Sen. Amy Klobuchar.

"All politics is local … I will continue focusing on issues important to Minnesota, and in the end it's why I'm going to be successful," Paulsen said. "I have been able to win it successfully over the years by focusing on the district."

Freshman Republican Rep. Tom Emmer, who has a primary opponent in the Sixth Congressional District, said he is not buying into fears that Trump's success would bring ruination to the GOP.

Emmer hasn't endorsed a presidential candidate but said he finds this new GOP debate lively, interesting and healthy. He hopes the discussion carries on all the way to the national convention this summer.

"Everyone is so afraid everything looks disunified or looks confused. Everybody wants to have everything sanitized and everybody wants everything perfect. It's supposed to be a little colorful and it's supposed to be about ideas," said Emmer, who pledged to support the party's nominee. "I'm really hoping for a convention, a real convention … to see Republicans get together in this environment and have an open, honest debate about where the party is going."

Does he worry about Trump turning off GOP voters and depressing voter turnout?

"People who worry about the top of the ticket, I think that's fair, but we're not here to ride those coattails," Emmer said. "If you want to just take the job lightly and ride the coattails, you'll live and die with who is at the top of the ticket. I think Minnesotans are just a little bit different. I think with Minnesotans, it's more personal."

A DFL view and 2 GOP takes

Paulsen and DFL Party Chair Ken Martin share similar sentiments about the Trump phenomenon — he is an unpredictable force who could draw a new band of voters who haven't been involved with either party.

Martin is not banking on a Trump nomination guaranteeing a win for Democrats. He says the race conjures memories of 1998, when independent pro wrestler Jesse Ventura won the Minnesota governor's race with 36.9 percent of the vote in a three-way race. At the time, Ventura ran on a platform against "politics as usual," a strong anti-establishment message that Martin notes sounds a lot like Trump.

"He [Trump] is tapping into frustration and anger partly among white working class people. These are folks who are working harder than they ever have before and making the same amount of money," Martin said. "I've been very careful in my party not to dismiss him. People think because of his theatrics and his divisive rhetoric … he will be easy to beat, but I think it's hard to say what impact he will truly have."

Retiring GOP Rep. John Kline, who campaigned for Rubio earlier this week in North Carolina, said he worries about Republicans being hurt by Trump and Democrats being invigorated by his statements against Muslims, immigrants and women.

"If Donald Trump is our nominee, that will push for a larger Democrat turnout because of their dislike or distaste," Kline said. "And it will suppress, to some degree, Republican turnout. It puts pressure down ballot and it makes it harder for Republicans to keep the Senate. … It makes it tougher for swing districts."

Former Republican Gov. Tim Pawlenty called what's happening in GOP politics an "experiment unfolding in real time."

"It's going to be very difficult for people to predict the net effect Trump will have," said Pawlenty, who also backs Rubio. "He hasn't begun to take the campaign to the general audience or to the Clintons yet. If he becomes the nominee, he'll mess with the Clintons in a way they've never been messed with before."

Allison Sherry • 202-383-6120