Van Drew cruised to reelection in November by a 20-point margin in a legislative district that Republican Gov. Christie carried easily.
"The fact that the governor won Cape May County by almost 50 points is particularly indicative of Sen. Van Drew's cross-party appeal and ability to get votes from all over the political spectrum," the chairs wrote.
Van Drew is the first Democrat to represent the First District in the state Senate in 100 years, the letter said.
Van Drew's legislative office did not respond to a request for comment, but his chief of staff, Allison Murphy, told the Atlantic City Press on Tuesday that Van Drew plans to announce his decision in the coming weeks.
"He has a proven track record of getting votes in difficult districts," she said.
National Democrats are eyeing the Second District seat as a possible steal. After October's partial government shutdown, which damaged GOP poll numbers, the nonpartisan Cook Political Report moved the seat from "solid Republican" to "likely Republican."
LoBiondo, who has been in office since 1995, holds one of just 17 Republican seats in districts that President Obama won last year. LoBiondo's campaign manager has said he will seek reelection in 2014.
Candidates must file petitions by March 31 to be on the June primary ballot.