ROBERT SIEGEL, HOST:
While Mitt Romney's loss in Colorado was especially surprising, his campaign can at least say that it won in one county that's always worth watching, Arapahoe. It reaches from the Denver suburbs deep into the cattle and wheat farms to the east. As NPR's Carrie Kahn reports, Arapahoe has been on the winning side in nearly every presidential election of the past four decades.
CARRIE KAHN, BYLINE: The multipurpose room at Foxridge Middle School was packed last night with caucus voters.
UNIDENTIFIED MAN 1: Ladies and gentlemen, are you ready?
KAHN: The school is in the southern suburbs of Arapahoe County, near the city of Centennial. But when you ask where people live, they tell you the name of the housing subdivision. Tuscany, Tuscany South...
MARY MARKS: Greenfield.
KAHN: That's where Mary Marks and her husband, Kenny, live. They own a computer company. She says she figured Romney would win the nomination, so she gave one last vote for the guy she calls the real conservative, Rick Santorum.
MARKS: I like that Santorum had a good showing so that he can push Romney to the right.
KAHN: Santorum won Colorado, along with two other states last night, but he did not win the key county of Arapahoe.
UNIDENTIFIED WOMAN 1: Mitt Romney, Mitt Romney, Newt Gingrich, Mitt Romney...
KAHN: As the votes were pulled out of a paper bag for tallying in Precinct 380, Romney was the winner. Countywide, he won by 200 votes or about 11 percent.
SETH MASKET: Arapahoe County's been considered kind of a bellwether county in recent elections.
KAHN: Seth Masket, a political scientist at the University of Denver says not too long ago, Arapahoe was solidly Republican. But as it's become competitive, it's also become a predictor, going with the winner in presidential and gubernatorial elections.
MASKET: It usually swings pretty widely, and that's because kind of the makeup of the county. It covers a lot of ground. It both covers a very urban area, the city of Aurora, and stretches pretty far to the east into some very rural territory.
KAHN: Independents make up about 30 percent of the voter registration in the county. So Masket says moderation is the key to success and that goes for Democrats, too.
ALFONSO NUNEZ: Come on in. These are my girls.
NUNEZ: Alma(ph), nina...
KAHN: Alfonso Nunez is a lifelong Democrat, but has been known to vote Republican. He's in the kitchen of his Mexican restaurant, La Queva(ph). It's been in the family since the 1970s in Aurora, the urban core of the county and Colorado's third largest city.
What's the special this weekend?
NUNEZ: You know, I haven't decided yet. I still have a lobster sauce that I was toying around in my head to go on top of a nice tilapia, but I'm not sure if that's going to be it yet or not so.
KAHN: Nunez hasn't made his presidential choice yet either. He voted for Obama last time, but isn't happy with the state of the economy. He says the president should have tackled that before going after health care. And he's still waiting for that comprehensive immigration overhaul that Mr. Obama promised.
NUNEZ: There's a lot of things that go into the way I vote, unfortunately. I know I'm just one vote, but whoever I vote for is going to have to earn it.
KAHN: Back at the Republican caucus, picking the moderate was exactly what Jaime Wollman did last night. She said she really wanted to vote for someone more conservative, but in the end went for Romney.
JAIME WOLLMAN: He is the only one who has an opportunity to get independent votes.
KAHN: But this was not a night for independent votes. In a caucuses that brought out just 6 percent of the state's Republicans, the desire to vote for a conservative held sway. Carrie Kahn, NPR News, Denver.