Betsy Markey is expected to become the second Democratic congressional candidate in Colorado to receive the endorsement of the National Rifle Association this week.
A spokesman for Markey's Republican opponent, Cory Gardner, told the National Review on Wednesday that "the NRA told [the Gardner campaign] they were endorsing Betsy Markey."
Markey, a freshman representing a district that hasn't elected another Democratic representative since the early 70's, is locked in an extremely competitive reelection battle. Earlier this month, Democrats scrambled to refute a New York Times story that suggested the party considered Markey's seat a lost cause.
Gardner was endorsed by the National Association for Gun Rights last week.
Earlier this week, the NRA also announced its support for John Salazar, another Democratic incumbent facing a tough reelection bid in a conservative district.