It seems like they're all coming out against the Second Amendment... 

Hunter Walker for BusinessInsider.com reports:

Former Maryland Gov. Martin O'Malley (D) seems set to make gun control a cornerstone of his 2016 presidential campaign. He kicked off what his aides describe as a "major push" on the issue last week with an email to supporters where he declared he was "pissed" by the mass shooting in South Carolina.

Gun control has long been something of a political lightning rod and President Barack Obama suffered one of the biggest defeats of his administration when he made a major push for a package of gun control legislation following the Sandy Hook elementary School shooting in late 2012. While some politicians have been reluctant to confront guns, O'Malley campaign spokeswoman Haley Morris told Business Insider he has been "fearless" on the issue and plans to make it a prominent part of his 2016 platform.

....O'Malley's presidential campaign has been characterized by staking out clear-cut liberal positions on major issues as he takes on Democratic frontrunner Hillary Clinton. Pushing for gun control actually puts him to the left of another liberal primary rival to Clinton, Sen. Bernie Sanders (I-Vermont), who has a voting record in line with his home state's light gun control laws.

Read the rest of the story at BusinessInsider.com.