Iowa Caucuses Appeal to the Most Colorful and Passionate Voters

— -- After hosting months of furious campaigning, countless town halls, numerous Donald Trump rallies, and plenty of candidate diner drop-ins, the state of Iowa finally caucuses tonight.

A sizable number of voters remain undecided hours before the caucusing begins, but many of their friends and neighbors have picked a candidate and are campaigning for him or her in force.

From the Jeb Bush backer whose whoops can be heard across auditoriums to supporters in superhero outfits to die-hard fans with homemade Bernie Sanders T-shirts, here are the most colorful and passionate characters ABC News reporters have encountered in Iowa: