“If he endorsed someone, for me, that person would be worth looking at,” said Nora Dirkx, a mother and home-schooler who came to the Carroll appearance along with her husband, Dan, and their 11 children.

Early polls continue to show Mr. Huckabee as the favorite in Iowa.

“I have told many of these candidates that they may make Huckabee’s decision for him,” Mr. Vander Plaats said. “If a Pawlenty or Thune or Bachman catch fire among the base, I could see Huckabee saying, ‘I think I will sit this one out.’ “