Well, he did promise to spend $50 million dollars to try to defeat pro-Constitution candidates. From the Washington Post:

The gun-control group founded by former New York mayor Michael R. Bloomberg will begin surveying all federal candidates in the 2014 midterm elections on gun issues Monday as it tries to become a political counterweight to the National Rifle Association.

This is the first big step by Bloomberg — who has committed to spending $50 million of his personal fortune this year to build a national grass-roots movement that will pressure lawmakers to pass more restrictive gun laws — to devise a political strategy heading into the November elections.

Bloomberg’s group, Everytown for Gun Safety, is asking all Senate and House incumbents and candidates to complete a 10-part questionnaire stating publicly where they stand on issues such as expanding background checks for gun buyers, limiting the capacity of ammunition magazines and toughening gun-trafficking statutes.

You can find the survey here though it’s a “slide show” so you have to answer each question to see the next one.