Although Colorado was overshadowed by the Ohio “firewall” and the large southeastern battlegrounds, the Centennial State provided Obama with the decisive 270th electoral vote for the second consecutive presidential election. Colorado selected Obama by a 4.8-point margin—far more than Obama’s 3-point victory in the national popular vote. If the Republicans plan on mounting a comeback in 2016, their efforts should begin by figuring out what went wrong in the Denver suburbs and developing a plan to correct it.

Perhaps no state captures the challenges facing Republicans better than Colorado. The changes in the composition of the two parties over the last decade have almost exclusively worked to the advantage of Democrats in Colorado, who reap the benefits of a growing Hispanic population and gains among well-educated, socially moderate suburbanites without suffering the losses among white Southern and Appalachian voters that cut against their gains in Florida, Ohio, Virginia, and Pennsylvania. As a result, Colorado voted slightly more for the president over the last two elections than the nation as a whole, even though the state leaned Republican in all but one presidential election since 1948.

President Obama’s successes in Colorado are hardly anomalous: Republican gubernatorial, senate, and presidential candidates have lost seven consecutive statewide elections over the last eight years, topping out at just 46.4 percent of the vote since Bush's win eight years ago. And Republicans can’t argue they didn’t have a fair chance: only President Obama could claim the full advantages of incumbency, since Michael Bennet was appointed to the Senate. The ability of Colorado's Democratic candidates to prevail in 2010's hostile political climate might be a telling indicator of the resilience of Democratic gains.

Although Colorado only possesses nine electoral votes, the GOP's alternative routes to 270 are bleak. It requires Republicans to pick-off one of Iowa, Wisconsin, or New Hampshire, three states with a stronger Democratic tradition, or Pennsylvania, where the GOP’s path to victory requires gains in Philadelphia suburbs not too dissimilar from those outside of Denver. And although it’s conceivable that a Republican could carry Virginia but lose Colorado, the two well-educated states are likely to go hand-in-hand. Loudon, Larimer, and Jefferson Counties will probably vote the same direction, and their states will probably follow suit.

Republicans have struggled mightily in Colorado for nearly a decade and a comeback will require the GOP to confront and overcome the forces imperiling their chances nationally. That makes the state tough for Republicans, but if the GOP can't unlock Colorado, they will struggle to find alternative routes to the presidency. Conversely, whatever Republican adjustments might permit a GOP breakthrough in Colorado would probably yield gains in demographically similar areas elsewhere, allowing them to reclaim Virginia and turn Pennsylvania into a dead-heat. In other words, if the GOP can't win back the Centennial State over the next four years, they're not likely to win back the White House.