An outside conservative group is airing advertisements beginning Tuesday attacking Democratic lawmakers seeking Senate seats because they voted for the 2010 health care bill.
The lawmakers also repeated President Barack Obama's now-discredited assurance that people with private health care could keep their coverage if they liked it.
The group Americans for Prosperity is spending $1.8 million against Democrats seeking Senate seats in Iowa and Michigan, states carried by Obama in 2012, but where Republicans now see an opening.
Democratic Reps. Bruce Braley of Iowa and Gary Peters of Michigan join a string of vulnerable Democrats in Southern states under attack by the group.
Democrats hold a six-seat edge in the Senate.