The National Rifle Association and new pro-gun control groups headed by former Rep. Gabby Giffords and Michael Bloomberg are in an arms race since a background check bill failed in the Senate last month. Politico reports that the adversaries are ramping up their fundraising, airing attack ads, and revving up their grassroots machines. The NRA announced a $25,000 week-long television ad buy to support Sen. Kelly Ayotte (R-NH), who's been under attack by gun control groups for her vote on the Senate bill. Giffords' Americans for Responsible Solutions said it raised more than $11 million in its first four months, a staggering figure even in the age of super PACs and big outside money groups. “The resource mismatch was always extreme and now it is basically gone,” said Matt Bennett of the think tank Third Way, which wants to strengthen gun control laws. Giffords’ group reported 366,000 members and donations from 53,500 donors. The NRA's membership has grown to a record 5 million, and it spent $18 million on the 2012 election.