Rep. Rush Holt (D-N.J.) will retire at the end of his term, opening up a safe seat for Democrats that's expected to draw a number of candidates in the primary.
Holt said in an email to supporters that there is "no hidden motive" for his decision to retire; rather, he wants to pursue other projects.
"As friends who have worked with me know, I have never thought that the primary purpose of my work was re-election and I have never intended to make service in the House my entire career," he said. "For a variety of reasons, personal and professional, all of them positive and optimistic, the end of this year seems to me to be the right time to step aside and ask the voters to select the next representative."