U.S. Communists have been running for office for decades. Above, the Party's presidential ticket in 1936. Ken Rudin collection hide caption

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Running mates? Mitt Romney greets former Gov. Mike Huckabee after taking part in a Republican presidential forum on Huckabee's Fox News program on Dec. 3, 2011. Henny Ray Abrams/AP hide caption

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Rick Santorum holds his youngest child, Isabella, before announcing his run for the presidency on June 6 in Somerset, Pa. Santorum's campaign announced Friday that Isabella, who was born with trisomy 18, had returned to the hospital. Jeff Swensen/Getty Images hide caption

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