“There has never really been an effective counterweight to the NRA — at least in terms of dollars, cents and the ability to get a message out,” said Stefan Friedman, a spokesman for Bloomberg’s new super PAC, Independence USA. “I think the mayor’s been clear this is an issue he cares very passionately about and this could very well be a curtain-raiser to the future.”

Bloomberg formed his super PAC in mid-October and announced it had a budget of up to $15 million devoted to the 2012 elections. He described three criteria for potential beneficiaries, starting with candidates who “will help protect Americans from the scourge of gun violence.” (The others were support for education reform and gay marriage.) So far, he’s helping least five House candidates as well as Democratic Pennsylvania attorney general hopeful Kathleen Kane…

Friedman said Bloomberg’s new super PAC could change that equation — at least in the races he’s involved in this year. “If the mayor can provide that [counterweight] and help some of the candidates, he’s eager to do that,” Friedman said. “This is the first time the NRA has faced a significant, equally funded foe in these districts.”

In addition to his super PAC activity, Bloomberg recently got involved in the Maine Senate race of former governor and fellow independent Angus King. He donated $500,000 to an outside group that bought ads for King and hosted an October fundraiser for King at his Manhattan home.