Letterman read his roster of "Signs Newt Gingrich Is Losing It" on Thursday's edition of his late-night talk show.
10. New campaign slogan: "What up, Gingsta?"
9. Since losing Iowa, he's married and divorced eight different women.
8. Has EMTs standing by at all times.
7. Quit campaign to buy a zoo with Matt Damon -- still in theaters, people.
6. When he hears the word "caucus," drops his pants and says, "I'll show you a caucus!"
5. In every speech, he attacks Walter Mondale.
4. His New Year's resolution? Be doughiest man he can be.
3. Makes cameo appearance in Casey Anthony's new video blog.
2. Losing it? When did he ever have it?
1. Claims he was born in Kenya.