Take longtime Democrat Debbie Smith. Four years ago, she wore the Obama T-shirts, went to his rallies, made her first campaign contribution and caucused for the first time.

“I wish to have my vote back,” said Smith, 51, a small business owner from Clive. “I feel completely responsible, and I feel like I need to tell people this.”…

La Suer was too young to vote in November 2008 or she would have cast a ballot for Obama, she said. But after studying health care and economics at the University of Iowa, she came to her own conclusions about the federal budget and economic policy.

“The big thing is I want to have a job when I graduate,” said La Suer, now 20. “Obama has promised that, and I don’t think we’ve seen the results that he’s promised.”

This summer, La Suer co-founded Students for Mitt Romney.