It's crunch time in Iowa, as the Republican Presidential candidates work to get undecided voters on their side.

FOX News Radio's Jessica Rosenthal reports from Des Moines, Iowa:

The undecided voters I've spoken to here - and a recent poll says there are 41% of them - say yes, the economy is very important, but they're also concerned about foreign policy and security.  This is Travis' first caucus, and he has no idea which candidate he'll go for.

(Travis) "I'm interested to hear what everyone has to say.  I know that they'll have supporters there, you know, for the candidates, talking about them.  So I'm interested to see what they say and maybe they'll persuade me one way or the other."

Polls do indicate Mitt Romney and Ron Paul are on top, with Rick Santorum in third.

In Des Moines, Jessica Rosenthal, FOX News Radio.