After the National Rifle Association endorsed Mitt Romney for president last Thursday, the group aired its first TV ad of the 2012 election season attacking President Obama.

The new ad accuses Obama of "chipping away at your rights, chipping away at your freedom." The NRA's political arm, NRA Political Victory Fund, said it would spend about $1.5 million this week to air the ad in Ohio, Virginia, Florida and Wisconsin, all critical battlegrounds. The group said it planned to air TV ads in swing states through Election Day.

When asked for the grand total the NRA-PVF planned to spend on ads, NRA-PVF spokesman Andrew Arulanandam said, "as much money as our members send us." The group said it would focus on targeted online advertising, in addition to television. NRA-PVF previously aired ads in January and February that attacked Obama for the Fast and Furious gun-tracking operation, Arulanandam said.

In the new TV ad, a narrator says: "Mountains of debt, threats to our sovereignty, chipping away at your rights, chipping away at your freedom. And now, they're attacking our Second Amendment rights, but you can stop them right now. Defend freedom, defeat Obama."

The mention of "sovereignty" refers to a proposed United Nations arms treaty the NRA fears will impose "burdensome" reporting requirements on civilian sales and gifts of guns. The Obama administration had entered into talks on the treaty, but those talks broke down in July, with the U.S. and other weapons-exporting nations saying more time was needed to reach agreement.

The ad could be seen on YouTube last Thursday, but NRA-PVF had not announced its plans to air it on TV. It began airing in Ohio Monday morning, according to the Campaign Media Analysis Group, which tracks political advertising.

As for Romney, he has said he does not support any new gun laws.