At a Saturday morning rally in Federal Hill Park, Baltimore, Martin O’Malley formally announced his run for the presidency.

You can watch video from O’Malley’s announcement below:

O’Malley, the former governor of Maryland and the former mayor of Baltimore, has long been speculated as a likely player in the 2016 Democratic primary.

He now joins Bernie Sanders (I-VT) as the second candidate to challenge Hillary Clinton for the Democratic nomination.

David Corn, writing in Mother Jones, opined that O’Malley was an ideal challenger in that he would “make a good sparring partner. He’s a smart guy with sass, but he’s not a slasher who could inflict long-lasting political damage.” In other words, he’s not too tame, but he doesn’t have that Sanders-esque streak of tempestuousness that might rock the boat.

As Jill Lawrence wrote last month, in anticipation of more non-Clinton candidates: “The Democratic side of the arena has finally come alive.”

Check out our primer on the 7 Things You Should Know About Martin O’Malley

Photo: Karen Murphy via Flickr.