“Suffering from a series of self-inflicted wounds and strategic mistakes by the NRCC, a number of their chosen candidates went down to defeat in their primaries. Those that made it through have all taken extreme positions far outside the mainstream in order to satisfy the right-wing fringe,” DCCC spokesman Ryan Rudominer said.

“The only thing outside the mainstream is the job-killing agenda House Democrats have pursued at the expense of middle-class families," NRCC spokesman Paul Lindsey responded. "It’s why their policies have been thoroughly rejected by the American people, and why Democratic candidates will be thoroughly rejected by voters in November.”

The DCCC is going particularly hard after Urquhart, labeling him an extremist and circulating a video in which he equates the separation of church and state with Nazism. In the video, Urquhart suggests church-state separation is a Nazi idea and says, “So the next time your liberal friends talk about separation of church and state, ask them why they’re Nazis.”

A spokesman for the Urquhart campaign, David Anderson, said the candidate has apologized repeatedly for the remark. Urquhart, he said, “believes 100 percent in religious freedom for all Americans.” Anderson said Urquhart was speaking out against the “oppression of religious freedom in the name of separation of church and state,” mentioning limits on school prayer and an attempt to force a veterans cemetery to remove a cross as examples. “The phrase he used was unfortunate, and he apologized for it,” Anderson said.

A Public Policy Polling survey released Thursday showed Democrat John Carney, a former lieutenant governor, leading Urquhart by 11 points, 48 percent to 37, among likely voters.