Transcript for Bloomberg Uses Own Funds for Gun Control Fight
George, back to you. This seems to be march madness. We're staying in washington now to the gun debate. The ban on awe salt weapons is going nowhere in congress. He's trying to save the rest of his legislation to stop gun violence are help from michael bloom berk. Reporter: He's the mayor of new york's largest city. He has something many other big city mayors don't, a personal fortune he's willing to spend. Today, pouring $12 million into two commercials supporting background checks for all gun purchases. They'll air in 13 key states from arizona to pen, where bloomberg believes senators are on the fence. I believe in the second amendment, I'll fight to protect it. With rights come responsibilities. That's why I support comprehensive background checks. Reporter: Mayor bloomberg said he knows he has public support. Recent polls show 90% of americans support criminal background checks for anyone purchasing a gun. Reporter: A second specicommercial trying to reassure people. They have nothing to do with taking guns away from anyone. Reporter: But the nra opposes the new legislation. On abc's "this week" karl rove echoed its concerns. If there's one thing that scares a lot of people that believe in the second amendment is the federal government keeping a national registry Reporter: The senate is expected to vote on what is left of gun control legislation when it returns from recess in april. Thank you, jim. Let's go to cecelilia vega now.
This transcript has been automatically generated and may not be 100% accurate.