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 plan Colorado stops on Monday. Only Ron Paul had no announced campaign plans.

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.

Gingrich told Denver's KOA-AM that he expects to do well here and other races in the West and South.

Most of Colorado's 36 delegates won't be assigned until after the state GOP assembly in April.