Booker’s announcement Thursday on Twitter ended months of speculation over whether the Democratic Party’s biggest draw would seek to challenge Gov. Chris Christie next year.

The Republican governor’s approval rating reached an all-time high after Superstorm Sandy.

There’s no word on whether Democratic Sen. Frank Lautenberg will retire.

Lautenberg is 88. Booker is 43.

His second term as mayor of the state’s biggest city ends in mid-2014.