The editors of the National Review have a message for Newt Gingrich: It's time to go. Rick Santorum is increasingly emerging as Mitt Romney's main challenger, as he overtakes Gingrich in contests won, delegates, and poll numbers, and the conservative magazine's editors want to see a Romney-Santorum contest. Gingrich is talented, but "it would be a grave mistake for the party to make someone with such poor judgment and persistent unpopularity its presidential nominee." When Gingrich was leading Santorum in the polls, he urged Santorum to quit. "On his own arguments the proper course for him now is to endorse Santorum and exit."