Unlike the 2010 GOP wave — where Republicans knocked off about 23 of the 54 members — a series of events converged early in the cycle that ensured even before Election Day the group would be nearly cut in half.

Twenty-seven members started off the 112th Congress. By Nov. 6, only 18 remained on the ballot after two abrupt resignations, three retirements, two primary defeats, a successful Senate campaign and the shooting of Rep. Gabrielle Giffords (D-Ariz.)

Cal Jillson, a professor at Southern Methodist University, said Republicans would have won many of those seats even if Blue Dogs remained on the ballot. He said that’s a sign the group is on the way out.

“I think we are seeing the waning days of the Blue Dog Coalition,” Jillson said. “Their numbers might be buttressed marginally in future elections but they’ll continue to be challenged in primaries and picked off in general elections.”