Clinton's stumped in Colorado twice in the space of a single week. (Photo by Doug Pensinger/Getty Images)

AURORA, Colo. - Asserting that women's reproductive rights are more at risk than at any time in the past 40 years, Hillary Rodham Clinton made an impassioned plea to the women of Colorado here Tuesday to reelect embattled Sen. Mark Udall and the rest of the Democratic ticket.

Clinton said women's rights - from equal pay to freedom of choice on abortion to affordable and accessible contraception - are central issues in the 2014 campaigns. "This election is important for everybody but it's especially important for the women of Colorado," she said.

The former secretary of state appeared at a rally that featured both Udall and Colorado Gov. John Hickenlooper, each of whom are in competitive races. Also appearing was former Colorado House speaker Andrew Romanoff, who is running against Rep. Mike Coffman (R ).

Udall's contest against Colorado Rep. Cory Gardner (R ) is one of the closest in the nation and Democratic strategists here say the outcome could hinge on the votes of unmarried women.

Clinton praised Udall as a Senate workhorse whose accomplishments don't make headlines but are crucial to the well-being of Colorado citizens. She saved her most passionate comments for the end, when she talked about the importance of the elections for women of the state.

She said the right to abortion "is under assault today across our country and is less secure than it has been at any time in the last 40 years. These Democrats will never shame and judge a woman for decisions that are complex and deeply personal." Those decisions, she said, should be between a woman, her family and her doctor, "not with her boss or a politician."

Clinton took note of the fact that Udall has been criticized for focusing so much attention on women's issues, to the point that he has been referred to as Mark "Uterus."

"As far as I'm concerned, and as far as Mark is concerned, when he fights for women's rights, he is fighting on the frontier of freedom," Clinton said. "Women's rights here at home and around the world are clearly at risk."

Without naming Gardner, Clinton took aim at him for having supported a so-called "personhood" amendment, which would legally recognize life as beginning at conception, and for attempting to run away from it.

This was the second time in a week that Clinton has campaigned in Colorado. First lady Michelle Obama is also scheduled to appear later this week, while former president Bill Clinton is expected to campaign in the state before election day.