Palin and Tebow stumble relative to the size of their stage: the larger it is, the harder they fall. As Alaska’s youngest governor, Sarah Palin was tough, with a reputation for rooting out corruption and preserving her state’s natural resources. “She’s exactly who this country needs,” said John McCain when he added her to his presidential ticket. But as a national political figure, Palin began to trip left and right.

When America dug deeper, it found she lacked basic map skills and knew frighteningly little about American foreign policy for a person one heart attack away from running the country. She also wondered aloud exactly what one did in the vice-president job that she was applying for and bumbled the mechanics of policy, health care, and tax code.

Likewise, Tebow was untouchable in college: he was the first sophomore in history to win the Heisman Trophy, and he led the Florida Gators to a national championship. College football is much slower and sloppier than its professional twin; in that forum, Tebow’s valiant efforts concealed his lack of polish. In the NFL, he has nowhere to hide. Since being promoted to starting quarterback, he regularly completes less than half the passes he throws in a game. He has been accused of slow and ugly throwing mechanics (one sports writer said you could time his release with a sundial). Critics say he can’t read the field after the snap and that at 6-foot-3 and 235 pounds he is the wrong size for his position, and shouldn’t play it at all.