MORRISON, Colo. - In 2008, Barack Obama used Colorado as both a stage for his nominating convention and a place to show how his new brand of politics could unite young voters, women and minorities to create a winning coalition even in places that normally back Republican presidential candidates.

Now Colorado has become an example of how hard it has been for Obama to maintain that coalition against the headwinds of a sour economy and his disastrous debate performance in Denver.

Republicans and Democrats alike agree that Colorado is a toss-up in this election. Like other battleground states, a slight Obama polling edge before October in Colorado has been transformed into a deadlock. That's because independent suburban women -- the key demographic -- are taking a second look at Romney.