Former Florida Gov. Jeb Bush had a tough week with his changing positions on the Iraq War and trying to explain whether he would have authorized it, knowing what we know now. Ross D. Franklin/AP hide caption

itoggle caption Ross D. Franklin/AP

Former Florida Gov. Jeb Bush is one of four "un-candidates" being targeted by liberal groups Campaign Legal Center and Democracy 21. They say the politicians have crossed the line into candidacy based on their activities in recent months. Scott Olson/Getty Images hide caption

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

itoggle caption Ken Rudin collection

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

itoggle caption Henny Ray Abrams/AP

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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The action was in Wisconsin Tuesday night, but Rick Santorum and his wife, Karen, had already moved on to his home state of Pennsylvania. They greeted supporters at an election night rally in Mars. Jason Cohn /Reuters /Landov hide caption

itoggle caption Jason Cohn /Reuters /Landov