Donald Trump is back in the lead in Iowa, but a new poll has a different Republican right on his heels.

FOX's Rachel Sutherland reports from Washington:

Quinnipiac University surveyed likely caucus-goers in Iowa and found Ted Cruz within two points of front-runner Donald Trump, 23 to 25%, respectively.

Cruz has surged since the attacks in Paris...

(Cruz) "We will have a commander-in-chief who stands up and says we will be defeat radical Islamic terror."

Ben Carson slipped to third place. Marco Rubio in fourth.

In Washington, Rachel Sutherland, FOX News.