SARASOTA, Fla. – Mitt Romney spent much of Thursday out of public view, huddling with advisers and speaking to donors at three high-dollar fundraisers, even as prominent conservatives griped about Romney's spare schedule.

Romney held one public rally Thursday, appearing on stage for roughly 20 minutes.

But the former Massachusetts governor was invigorated on the stump, nearly shouting himself hoarse at times as he seized on President Barack Obama's comment at a Univision forum that he couldn't change Washington from the inside.