Rep. Jeff Van Drew’s switch from the Democratic to Republican party leaves an open field for Democrats who are looking to unseat him next year.

One of the candidates is a well-known political science professor who has already secured early support from state Democratic heavyweights. Brigid Harrison has analyzed state politics and political races for nearly 30 years.

She says that Van Drew’s unwillingness to vote to impeach President Donald Trump was too much for her to bear.

“It was kind of a test. And you have to sit back and say, ‘I can’t sit silently anymore,’” Harrison says. “I've been sitting on the sidelines, helping New Jerseyans think about politics for the better part of 25 years. And nothing has compelled me to step off the sidelines.”

Even before Van Drew's party switch was official with a meeting in the Oval Office this past Friday, Harrison entered the race.

“It's about time that South Jersey has a woman running for Congress and a woman in Congress representing them,” she says.

Van Drew was a conservative Democrat during his days in the state Legislature. Now, in a district that backed Trump in 2016, he’s hoping the president's support will carry him to re-election in 2020.

“I think he's a much less formidable opponent than he was a week ago. I mean, I think Democrats and Republicans don't like someone who's disloyal,” Harrison says.

Harrison rolled out a list of endorsements last week, including Senate President Steve Sweeney and six Democratic county chairs.

“I think that anyone who has known me for any amount of time would laugh at the specter that I'm a machine candidate. I have been incredibly, incredibly critical of the machine,” he says.

Progressives frustrated by Van Drew may be reluctant to back Harrison. But she says, “Get to know me. First, do your research. Get to know me, talk to me. Honestly, I will tell you, my politics doesn't come from the progressive wing.”

Atlantic County Freeholder Ashley Bennett announced last week that she was also a candidate for the Democratic nomination.

The Democratic primary will be held in June.