There is perhaps no other state this election cycle that better reflects the lessons learned by both parties over the past four years than Colorado.

In 2010, Republicans discovered the hard way that a bad candidate who says impolitic things can squander a winnable Senate race in even the most favorable of climates. And Democrats learned they could overcome discouraging odds with a playbook centered on the women’s vote (highlighting abortion and contraception) and spotlighting an “extremist” opponent.

The Democrat, Michael Bennet, went on to defeat Republican Ken Buck by one percentage point, creating the only bright spot in a dismal midterm year for his party. Four years later, in the race between incumbent Mark Udall and Republican Cory Gardner, Democrats are employing the same strategy, only this time even better financed and waged with more intensity.

Since 2010, Republicans have gotten an education of their own, and this time nominated a candidate who is likeable, not prone to major gaffes, and open to moderating stances to fit a more libertarian-minded electorate. For Democrats, this means a more challenging dynamic in Take 2. Though the old strategy worked four years ago, they risk overplaying their hand this time.

Gardner entered the race with a significant liability: support for a state ballot measure that would define personhood as beginning at conception, thus rendering abortion and some forms of birth control illegal. Soon after entering the race, he withdrew his backing of the measure (though he kept his name on a similar bill in the U.S. House), which is a perennial loser in the state. But since the moment Gardner announced his candidacy, Democrats inside and outside of Colorado have hammered him on that original stance.

Nonetheless, the GOP challenger has been leading in every poll since mid-September. The RealClearPolitics polling average shows him up 3.8 …read more