Updated at 6:20 p.m. ET
Republican Sens. Lindsey Graham of South Carolina and Bill Cassidy of Louisiana defended their namesake health care bill Monday even as the measure ran into potentially fatal opposition from a third Senate colleague.
Sen. Susan Collins, R-Maine, came out against the bill, joining fellow Republicans Rand Paul of Kentucky and John McCain of Arizona. That leaves the GOP majority at least one vote short of the 50 votes needed to pass the bill over unified Democratic opposition.