Republican presidential candidate Sen. Marco Rubio (Fla). (Scott Olson/Getty Images)

CLIVE, Iowa — Marco Rubio’s presidential campaign previewed a 30-minute TV ad Saturday that his campaign plans to air in Iowa this weekend in the final hours before Monday’s all-important caucuses.

The Florida Republican senator’s campaign is billing the spot as a television special that will include footage from a recent town hall. It reflects his advisers’ belief that their best asset is their candidate and the most effective way to communicate is to expose his pitch to many voters as possible.

The campaign posted a sampling on YouTube.

The campaign says it plans to field questions on social media and on the phone while the ad is broadcast. It will air in Sioux City on Saturday and Sunday and in Des Moines, Cedar Rapids and Davenport on Sunday.

Rubio sits in third place in Iowa, recent polls show, running behind Donald Trump and Sen. Ted Cruz (R-Tex.).