WASHINGTON (AP) — Little more than a month after they backed sweeping changes to Medicare, Republicans are on the political defensive, losing a House seat long in their possession and exhibiting significant internal strains for the first time since last fall's election gains.

"We've got to get beyond this," Rep. Paul Ryan, R-Wis., said recently after several days of back and forth over the proposal he authored and included in the budget that cleared on a party line vote. "And we've got to get onto a serious conversation about what it takes to fix the fiscal problems in this country."

Under Ryan's proposal, Medicare would remain unchanged for those 55 or older, including the millions who now receive health care under the program. Anyone younger would be required to obtain coverage from a private insurer, with the government providing a subsidy to cover part of the cost of premiums.