The field of Democrats vying to oust Representative Jeff Van Drew got more crowded on Monday as Amy Kennedy, the wife of former Representative Patrick Kennedy, entered the race, bringing the instant name recognition of a political dynasty to an already robust group running for the New Jersey congressional seat.
Ms. Kennedy, who described herself as a former teacher and a mother of five in a minute-long YouTube video announcing her candidacy, did not mention Mr. Van Drew’s defection from the Democratic Party last month or his pledge of “undying support” for President Trump.
But the video did include an image of Mr. Van Drew shaking the president’s hand in the Oval Office as he announced he would join the Republicans, one day after the South Jersey lawmaker voted against impeaching Mr. Trump.
“Too many of our leaders have lost their moral compass,” she said in the video clip. “Trump and Van Drew are symptoms of a bigger sickness infecting our country and our politics.”
Ms. Kennedy’s husband is a former Rhode Island congressman and the son of former Senator Edward M. Kennedy of Massachusetts.
Mr. Van Drew, a first-term congressman and a former state senator, represents a congressional district the president won by about 5 points in 2016.
She went on to discuss what are likely to form the broad themes of her campaign: civility, climate change, mental health and addiction, and corporate tax incentives.
“We continue to ignore the biggest public health emergency of our time — the mental health and addiction crisis that affects virtually every family,” she said.
She added, “People in South Jersey can’t find good jobs, but the richest corporations pay almost no taxes.”
Four other Democrats have already entered the primary race in a district that cuts across New Jersey’s southernmost counties, stretching from Cape May to the Pennsylvania border.
Brigid Callahan Harrison, a professor who teaches political science at Montclair State University, announced her candidacy the same week Mr. Van Drew said he would join the Republicans, a shift that prompted most of his staff members to quit.
Professor Harrison was quickly endorsed by many of the Democratic Party leaders in the district who hold sway over whose name will appear on the party’s coveted ballot line.
Ashley Bennett, a freeholder representing Atlantic County who appeared on the cover of Time magazine with other progressive women, also has announced she would run for the Democratic nomination for the congressional seat.
Ms. Bennett has said she intends to focus on issues affecting New Jersey’s working class, and is likely to draw support from the state’s increasingly active grass-roots organizations.
John Francis III, a commissioner in West Cape May, and Robert Turkavage, a former F.B.I. agent who last month switched from the Republican Party to the Democratic Party, have also announced they will run in the Democratic primary.
At least three Republicans, including David Richter, a former businessman who has said he will spend $1 million of his own money on his campaign, are also expected to compete against Mr. Van Drew for the Republican nomination.