Massachusetts Attorney General Martha Coakley will run for governor of Massachusetts in 2014, she announced Monday, joining a crowded Democratic contest she is poised to begin as a front-running candidate.

Coakley announced her campaign in a two-minute Web video, casting herself as a populist who will fight for those who have worked hard and faced hardships.

"These folks are the reason I'm running for governor. They need someone who will fight for them, someone who will take their side," Coakley says.