In this Nov. 14, 2013 file photo, President Barack Obama pauses while speaking about his signature health care law, in the Brady Press Briefing Room of the White House in Washington. It survived the Supreme Court, a presidential election and numerous repeal votes in Congress, but now President Barack Obama's health care law risks coming unglued because of his own mistakes explaining it and his administration's bungled implementation. Obama now needs breakthroughs on three separate fronts: the cancellations mess, technology troubles, and a crisis in confidence among his own supporters. It's daunting, but working in his favor is evidence of pent-up demand for the program's benefits and an unlikely collaborator _ the insurance industry (AP Photo/Charles Dharapak, File)

(AP)—Republicans are seeing the troubled launch of President Barack Obama's signature health care overhaul as a chance to win more seats in the 2014 election, when control of Congress will be at stake.

Obama last week had to announce changes to the law after his earlier promise that Americans could keep the they liked fell apart. Millions of people have instead faced cancellation of their coverage.

That follows serious technical problems in the government website that launched Oct. 1 to help Americans find insurance under the new law.

The health care overhaul was supposed to be Obama's legacy. Instead, Republicans are already airing attack ads to prepare for next year's elections.

One target is Representative Nick Rahall in West Virginia, who was among 39 of Obama's fellow Democrats to vote Friday for a Republican measure that would let insurers continue selling policies to individuals that fall short of the health care law's requirements.

The shift from Democrats was an ominous sign for the White House.

"I'm concerned about my integrity with voters who have returned me here 38 years. They know me enough to know I wouldn't purposely mislead them," Rahall said.

Republicans are already compiling lists of dozens of Senate and House Democrats such as Rahall who once repeated Obama's pledge that voters' existing coverage would not be canceled.

Top Democrats, who need to gain 17 seats to retake the majority in the House of Representatives, say next November's elections are far off. They say the health care law will be working well by then.

But America Rising, a Republican political action committee, is collecting video of Democrats' comments on the health care law. Some conservative groups are already running television spots, with Americans for Prosperity airing ads attacking Rahall and fellow Democrat Sen. Kay Hagan.

The let insurers cancel some existing coverage that lacked the improved features that are now required. More than 4 million policyholders have received termination letters from their insurance carriers, according to an Associated Press count.

Obama on Thursday took administrative action to let insurers continue current plans for a year. He took the blame for the confusion.

Even so, most House Democrats felt Obama's action was not enough and demanded a vote on a Democratic proposal.

"They want to be on record," said Democratic Rep. Mike Doyle. "Members are not judged by administrative fixes. Members are judged by their voting records."