Rep. Rush D. Holt, the New Jersey Democrat who last year lost a special-election primary to now-Sen. Cory Booker, announced Tuesday he will not seek re-election to a ninth term.  

Holt, a physicist-turned-congressman, is the third member of the New Jersey delegation to either resign or not seek re-election in 2014. His 12th District, which includes Trenton, is not competitive for Republicans.  

“There is no hidden motive for my decision,” Holt said in a statement to supporters. “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. 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.”  

Holt first announced his retirement in an interview with The New York Times .  

Holt’s announcement comes on the same day Rep. Robert E. Andrews’ resignation became effective . Last year, GOP Rep. Jon Runyan of New Jersey announced he would not seek re-election in 2014.  

Holt now becomes the 19th House member to retire this cycle and not seek another office. For a full list of retirements check out Roll Call’s Casualty List .  

New Jersey’s 12th District is rated a Safe Democrat contest by Rothenberg Political Report/Roll Call. President Barack Obama carried the district by a 35-point margin in 2012.