Facing likely challenge from Cory Booker, NJ Sen. Lautenberg says he will retire

New Jersey Democratic Sen. Frank Lautenberg plans to retire, declining to seek reelection in 2014 in the face of a likely challenge from charismatic Newark Mayor Cory Booker. 

The 89-year-old lawmaker is the last remaining veteran of World War II in the Senate and has been elected easily five times. Lautenberg is a staunch advocate of gun control and public infrastructure and is a champion of the Amtrak railroad. 

But the expected challenge from Booker, who earlier was thought to be weighing a run for governor, meant Lautenberg would have been in for a tough primary battle. 

Lautenberg first won election to the Senate in 1982.

The Associated Press contributed to this report.