Republican Sen. Marco Rubio of Florida (left) makes remarks at CPAC 2013 on March 14. Jim DeMint (right), president of the Heritage Foundation, is shown during a news conference on immigration reform on May 6 in Washington, D.C. DPA/Landov; AP hide caption

itoggle caption DPA/Landov; AP

Sen. Jim DeMint's endorsement has become the gold standard for true blue conservatives seeking a Senate seat. Alex Wong/Getty Images hide caption

itoggle caption Alex Wong/Getty Images

Comedian Stephen Colbert told his supporters to ask South Carolina Gov. Nikki Haley to name him to replace outgoing Sen. Jim DeMint. Scott Gries/Picturegroup hide caption

itoggle caption Scott Gries/Picturegroup