Rove-backed 527 group airs ads attacking Tim Kaine

Former Virginia Gov. Tim Kaine.

RICHMOND, Va. (AP) - Get used to it. The first independent expenditure attack ad of the 2012 Senate race debuts Thursday in Virginia attacking Democrat Tim Kaine's 2012 Senate bid.

American Crossroads, a group that backs Republicans but acts independently of their campaigns, is spending $616,000 over two weeks to televise the 30-second ad in Virginia's four largest media markets.

The tax-exempt group can raise and spend money on issue advocacy as long as it doesn't directly urge a candidate's election or defeat. It is subject to far fewer public disclosure requirements than political action committees.

It's known among political pros and pundits as a "527 group." Swift Boat Veterans for Truth in 2004 was such a group.

The ad assails Kaine's relationship with President Barack Obama and his fiscal record as Virginia governor.