Rick Santorum will vote for Mitt Romney if the former Massachusetts governor wins the Republican presidential nomination, a spokeswoman said Friday. Alice Stewart, speaking on CNN\'s \"Starting Point,\" was trying to douse an uproar Santorum started Thursday when he suggested Romney is only \"a little different\" from President Obama, USA Today reported. \"Rick has made it abundantly clear once a nominee is chosen he\'ll stand behind the nominee and do everything we can to replace Barack Obama,\" Stewart said. Romney and former House Speaker Newt Gingrich piled on after Santorum\'s remark in San Antonio, joined by Republican bloggers. Ed Morrissey, a Santorum supporter, suggested the former U.S. senator had \"forgotten the purpose of the Republican primary.\" \"You win by giving people the opportunity to see a different vision for our country not someone who is just going to be a little different than the person in there,\" Santorum said. \"If they\'re going to be a little different we may as well stay with what we have instead of taking a risk in what may be the Etch A Sketch candidate for the future,\" a reference to a gaffe earlier this week by a Romney campaign spokesman. Santorum\'s campaign Friday highlighted Santorum\'s opposition to Obama with a political ad that paints a hypothetically bleak future for a fictional American town called \"Obamaville,\" The Hill reported. \"Imagine a small American town two years from now if Obama is re-elected,\" the voiceover in the ad says. \"Small businesses are struggling and families are worried about their jobs and their future. The wait to see a doctor is ever increasing, gas prices ... through the roof and their freedom of religion: under attack.\" The ad then shows images of Iranian President Mahmoud Ahmadinejad, warning \"Obamaville\" would also be under the cloud of a possible nuclear threat from a \"sworn enemy\" of the United States. \"Welcome to a place where one president\'s failed policies, really hit home. Welcome to Obamaville, more than a town, a cautionary tale,\" the ad said.