AP

Colorado GOP chairman says Rick Santorum has won state presidential caucuses.

With 99 percent reporting, the GOP is reporting that Santorum has received 40.2 percent of the vote. Mitt Romney, the next nearest competitor, got 34.9 percent.

Santorum also won the Missouri primary and Minnesota Republican caucuses Tuesday, raising questions about Romney's appeal with conservatives at the core of the Republican Party.

Both Santorum and Romney made last-minute visits to Colorado on the morning before the caucuses.

Caucus attendance statewide was about 65,000. That was down from 70,000 four years ago, when Colorado shared the spotlight with more states on a Super Tuesday date. Republican leaders had predicted a turnout of 70,000 to 80,000 people.

The lower turnout could be a result of a few inches of fresh snow that fell Tuesday in some parts of the state. But Republicans saw lower turnout in all three states making presidential decisions Tuesday.

The decision by voters in Colorado's caucus is not binding during the election process. UCCS political science professor Josh Dunn says it's mainly about momentum.