Republicans aren’t exactly rolling out the red carpet for Jeff Van Drew.

The New Jersey Democratic congressman may have hoped his defection to the GOP would ease his path to reelection in a conservative-leaning district. His political prospects as a Democrat had been imperiled by his opposition to impeaching President Donald Trump, which outraged activists and party officials.

But before he even officially switches parties, Van Drew is facing firm opposition from multiple Republicans who were already running for the 2nd District nomination, as well as local GOP leaders and activists skeptical of his voting record and longstanding ties to the state’s Democratic machine. It all promises to make the South Jersey House race one of the most competitive and closely watched in the country.

“He was desperate to save himself,” said Bob Patterson, one of the GOP candidates in the district, which includes Atlantic, Cape May, Cumberland, and Salem Counties. “He knows he’s in a Trump district. He knows he would lose. He made a very specific calculation.”

Van Drew has yet to publicly address his plans to switch parties, which were reportedly finalized with Trump’s encouragement and prompted the resignation of a half-dozen senior aides over the weekend. Multiple calls to Van Drew and his office weren’t returned. The National Republican Congressional Committee, the House GOP’s campaign arm, declined to comment.

And it remains to be seen if Trump, who tweeted approvingly of the move but has said nothing else, will ultimately campaign hard for the longtime Democrat in a GOP primary.

Even State Sen. Michael Testa, who co-chair’s Trump’s reelection campaign in New Jersey, only voiced support for Van Drew in the context of a Trump endorsement.

“We have mutually agreed to follow President Donald J. Trump’s lead on the issue,” said Testa, referring to the Cape May County GOP, which he also chairs. “We expect all county committee members and local elected Republicans will join us.”

But other party leaders were singing a different tune.

“He will have to prove he is with us on more than just the issue of impeachment,” said Jacci Vigilante, chair of the Gloucester County GOP. She said Van Drew is welcome to join Republicans, but will need to denounce his affiliation with people like South Jersey Democratic power broker George E. Norcross III to “earn their trust.”

Recent history hasn’t been kind to party-switchers like Van Drew. Former Alabama Rep. Parker Griffith, a longtime Democrat, defected to Republicans in 2009, only to lose in a GOP primary the next year. That same election cycle, Pennsylvania Republican Sen. Arlen Specter bolted to the Democrats before losing the 2010 primary to Joe Sestak.

“I think what [Van Drew] did was admirable,” said Shanin Specter, the late Arlen Specter’s son. “I’m talking about this decision to put his beliefs about the appropriateness of the impeachment inquiry over this party affiliation." Specter, who said he supports impeaching Trump, said Van Drew’s alienation from Democrats echoed "the same circumstance that my father faced in the Republican Party.”

There are some differences between Van Drew, who has largely voted with Democrats in Congress, and Specter, who had a more independent voting record. Van Drew has voted with Trump only 7% of the time since taking office for his first term this year, according to a tally by the website FiveThirtyEight. The only two votes on which he both bucked Democratic leadership and backed Trump were related to impeachment.

Van Drew also has a 100% rating from the Planned Parenthood Action Fund and recently endorsed New Jersey Democratic Sen. Cory Booker for president.

“The Republican voters in the 2nd District are certainly loyal to the President, [but] I don’t think they’re going to put their support behind a lifelong Democrat,” said David Richter, a leading GOP candidate who also vowed to stay in the 2020 primary race.

“I wish more people would leave the Democratic Party,” Richter said. “But if you do it opportunistically, [it] just smacks of being ... very fake.”

J.J. Balaban, a Democratic strategist who helped engineer Sestak’s primary victory over Specter, predicted that Van Drew will receive support from the GOP nationally but have a tougher time with local Republicans.

“These are people whose job it was to defeat him until 24 hours ago," said Balaban, who has made TV ads supporting Van Drew but said he would no longer do so. “So turning around on a dime and saying, ‘We love you,’ it’s not going to be that easy.”

Van Drew likely had no other option if he wanted to stay in office. Just like Specter’s vote in favor of then-President Barack Obama’s economic stimulus plan made Specter toxic in a GOP primary, Van Drew’s opposition to Trump’s impeachment might have made a Democratic primary unwinnable. A recent poll found that only 24% of likely Democratic voters in the district thought Van Drew deserved to be reelected.

Van Drew is also moving to a party that’s decidedly bearish on its 2020 election prospects in House races. As of Dec. 4, 21 Republican House members — 10% of the GOP caucus — had announced they will be retiring from Congress, compared with only eight Democrats.

At least one Van Drew donor, New Jersey Democratic Rep. Frank Pallone, said he’d be asking for a refund. Pallone’s political action committee, Shore PAC, gave Van Drew’s campaign $10,000 in 2019. Several of Van Drew’s other big Democratic contributors said Monday that they were waiting to hear publicly from him before asking for refunds.

And for all of Democrats’ condemnation of Van Drew, they may be hard-pressed to win the district without him. They tried for years, and Van Drew was seen as a major recruiting coup before prevailing in 2018. The nonpartisan Cook Political Report, which handicaps House races, on Monday changed its rating for the race from “Toss Up” to “Lean Republican.”

All three of the declared Republican candidates in the race said Monday that they’re not dropping out. For now, Van Drew’s saving grace in a Republican primary might be if they stick around and split the opposing vote. He could then find a friendly reception in a general election in the Trump-friendly district.

“I like Jeff and I think it’s great," said Colette Kraus, an Egg Harbor Township independent who voted for Trump in 2016. “I think he really does care about the people in this area. He truly is everywhere."

“I’m for Trump, and [Van Drew] is so against what’s going on with the Democrats and the impeachment, so I’m for him," said Hilda Burnley, 71, an independent voter in Weymouth Township. ”If he’s for Trump at all, I’m for him.”

Staff writer Amy S. Rosenberg contributed to this article.