DENVER (AP) -- Three of four Republican candidates for president are in Colorado, trying to pin down support in Tuesday's precinct caucuses.

Mitt Romney, Rick Santorum and Newt Gingrich all had Colorado stops on their agendas Monday. Only Ron Paul had no announced plans to hold a campaign event here.

Republicans say they've been getting plenty of phone calls in recent days from campaigns seeking their support. Tuesday's precinct caucuses are nonbinding, but they can show support for the various campaigns.

Romney won Colorado's caucuses in 2008 and is considered the favorite this year. Most of Colorado's 36 delegates won't be assigned until after the state GOP assembly in April.

Democrats also hold precinct caucuses next month. But because Democrats have no presidential nominating race, the Democratic caucuses will concern only local races.

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