The 2010 TIME 100

Who'd have thought a history buff with a quirky sense of humor and a chalkboard could make for such riveting television? Glenn's like the high school government teacher so many wish they'd had, charting and connecting ideas with chalk-dusted fingers — kicking it old school — instead of becoming just another talking-heads show host. Self-taught, he's become America's professor of common sense, sharing earnestly sought knowledge with an audience hungry for truth. Glenn, 46, tackles topics other news shows would regard as arcane. Consider his desire to teach Americans about the history of the progressive movement: he's doing to progressive what Ronald Reagan did to liberal — explaining that it's a damaged brand.

His love of the Founding Fathers inspires others to learn and respect our nation's history. Best of all, Glenn delights in driving the self-proclaimed powers-that-be crazy. (The whole country awaits the red phone ringing!) Even his critics (whom he annihilates in ratings) have to admire his amazing ability to galvanize everyday Americans to better themselves and peacefully engage their government. Though he sometimes dismisses himself as an aw-shucks guy or just a "rodeo clown," he's really an inspiring patriot who was once at the bottom but now makes a much needed difference from the very, very top.

Palin, a former governor of Alaska, was the Republican candidate for Vice President in 2008

TIME 100 Social-Networking Index: 621,436