Rep. Cory Gardner (R-Colo.), left, and Sen. Mark Udall, (D-Colo.) (AP)

GREENWOOD VILLAGE, Colo. -- Senators from the same state usually go out of their way to maintain healthy relationships with each other, even if they are in different parties. But the Colorado Republican hoping to oust Sen. Mark Udall (D) takes a dim view of his state's other Democratic senator, whom he hopes to serve alongside.

In an interview, Rep. Cory Gardner (R) criticized Sen. Michael Bennet (D), head of the Democratic Senatorial Campaign Committee, for advertisements Gardner said were "deceitful."

"Michael Bennet, who has portrayed himself as this go-along, get-along, above-the-partisan-fray type of senator, now has to show that he's a true partisan, in his chief role as the chief partisan for the Democratic Party," Gardner said. "So here in Colorado, Michael Bennet is showing his true colors as the chief partisan of the United States Senate."

"He's revealed who he is," Gardner went on. "Because he's been saying all along that the Colorado delegation works well together, but unfortunately Sen. Bennet I guess has decided that deceitful advertisements is the only way he can keep his job, and the only way that he and Mark Udall can continue to support the failed policies of this president."

For months, Democrats have used Gardner's support for various measures that would limit access to abortion to portray him as out of touch with Colorado. In an advertisement released late last month, the DSCC called Gardner "extreme," citing measures he had sponsored to ban abortion. Udall has criticized Gardner's past support for so-called "personhood" legislation; another personhood measure will be on Colorado's ballot this fall.

Guy Cecil, the DSCC's executive director, sounded similar themes in a response to Gardner's comments.

“Congressman Gardner sounds like a very desperate politician who is upset that voters are learning the truth about him and his record," Cecil said in an e-mail. "Congressman Gardner would be better off spending his time explaining to the women of Colorado why he should be the one making their health care decisions and why he continues to sponsor federal legislation to ban and criminalize their right to make those decisions."

The effort to drive a wedge between Gardner and women voters has taken a toll. Public polling shows the race between Gardner and Udall in a statistical dead heat, with a pronounced gender gap in which women overwhelmingly favor Udall and men pick Gardner by a wide margin.

Gardner has moved to counter Democrats' attempts to fit him in the War on Women narrative. In a new advertisement of his own, Gardner says he favors making the birth control pill available "over the counter, round the clock, without a prescription." Gardner said he will vote against the personhood amendment on this year's ballot.

"I don't support personhood. I oppose personhood," Gardner said.