Jeff Van Drew’s switch from Democrat to Republican last year was a political tsunami capped by the South Jersey congressman’s pledge of “undying support” for President Donald Trump.

But in his quest to keep his seat, Van Drew is having it both ways: He now has a controversial Democratic operative working for him again as his closely watched race against Democrat Amy Kennedy nears its finish.

The operative, Craig Callaway, worked on behalf of Kennedy in her successful primary campaign. But he says a falling-out led him to reconnect with Van Drew — wrangling mail ballots in part by paying people to act as messengers, which is legal. His operation organizes multiple trips to the Atlantic County elections board to drop off ballots, where each messenger is limited by New Jersey law to three ballots total — requiring a vast network of messengers to make a difference.

His work could help Van Drew cut into Kennedy’s support in Atlantic County.

“I’m a consultant,” Callaway, a former Atlantic City Council president who served time in federal prison on bribery and related charges, said in a phone interview this week. “I’m a businessperson. I’m supportive of Democratic candidates. But I have a sense of independence.”

The Atlantic City Democratic Committee, which is headed by Callaway’s sister Gwen Lewis and backed Kennedy in the primary, still supports the Democratic nominee.

“I’m a Democrat, always have been and always will be,” Lewis said.

But her brother said he cast his own mail ballot for Van Drew, whose campaign has paid Callaway $110,00 over the last two months for get-out-the-vote efforts, according to Federal Election Commission reports. He’s angry at the Kennedy campaign and said officials there were “not people who keep their word" and “not even close to honorable.”

“Van Drew and I, we have a relationship,” Callaway said. “Beyond political. Even though I didn’t agree, and I still don’t agree with his move, as far as supporting Trump, I still say he’s an honorable man.”

» READ MORE: Jeff Van Drew has been winning South Jersey elections for decades. Can he do it as a Republican?

Callaway has worked for Republicans before, including former Atlantic City Mayor Don Guardian, who won a term with Callaway’s help — then lost when Callaway supported his opponent the next time around. That opponent was former Mayor Frank Gilliam, who later resigned after pleading guilty to wire fraud and is awaiting sentencing.

Callaway’s support, and ability to collect significant numbers of mail ballots, is seen as crucial in Atlantic City elections. But the sprawling 2nd Congressional District encompasses much more than Atlantic City: It stretches from the Philadelphia suburbs in Gloucester County south to Cape May, includes Cumberland and Salem Counties, and stretches north of Atlantic City into Burlington County.

As of Monday afternoon, more than 2.5 million people had already voted in New Jersey, about 63% of the total 2016 turnout.

As a Republican, Van Drew has worked in the campaign’s closing weeks to shore up support among those who backed him as a conservative Democrat, including Atlantic City’s Bangladeshi community.

Ron Filam, Van Drew’s campaign manager, did not return phone calls seeking comment about the campaign’s work with Callaway.

Josh Roesch, Kennedy’s campaign manager, declined to comment about Callaway’s involvement with either campaign.

The race is expected to be one of the most competitive congressional elections in the country. Kennedy, a former public schoolteacher who is married to ex-U.S. Rep. Patrick Kennedy, is vastly outspending Van Drew on TV ads. She’s also counting on a vast network of volunteers, many of them women, who have been phone-banking on her behalf for months.

Van Drew has said voters will ultimately support him despite his party switch for the same reason they have in elections since the 1990s. “I’m the same person,” he said in an interview this month. “I was always moderate to conservative, and there were always folks when I was a Blue Dog Democrat who wouldn’t support me. This is who I am.”

House Majority PAC, a super PAC allied with House Democrats, has been funding TV ads mocking the well-dressed Van Drew for both politics and vanity, with one showing a likeness of Van Drew being fitted for a suit by a tailor and looking at himself in the mirror. “Looking good. It’s Jeff Van Drew’s thing. Doing good … not so much,” the voice-over says.

» READ MORE: The Kennedys will soon be gone in Congress. Unless Amy Kennedy beats Jeff Van Drew in New Jersey.

The local Democratic Party is eager to take out Van Drew after the longtime Democrat voted against impeaching Trump and left the party.

Michael Suleiman, the chair of the Atlantic County Democratic Party — and the person who initially warned Van Drew the party would not support him if he opposed impeachment — said Callaway would have to deal with the fallout of his embrace of Van Drew.

“We plan on winning this race for Amy Kennedy,” Suleiman said. “I’m not taking my eyes off the prize."

“He’s got to answer to a lot of people in the Black and brown community,” he said of Callaway. "Why the hell is he pushing a guy who’s pledged undying support to a racist xenophobe?”