Corn is big business in Iowa, which has usually made anything but support for ethanol subsidies off-limits for presidential hopefuls. Steve Pope/AP hide caption

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Former Massachusetts Gov. Mitt Romney focuses on a key issue — corn — in Ankeny, Iowa, on Friday, as he prepares to launch his 2012 presidential bid. Charlie Neibergall/AP hide caption

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George Romney with his wife, Lenore, and teenage son Mitt, after announcing he would seek the Republican nomination for governor of Michigan at a press conference in 1962. AP hide caption

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Republican Sen. Rand Paul of Kentucky sharply criticized the Obama administration's decision to intervene in Libya. Brendan Hoffman/Getty Images hide caption

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