Tom Murphy, 56, in his home in Gainesville, Va., was diagnosed with ALS four years ago. An experimental drug seems to have slowed the progression of his disease, he says, though most ALS patients aren't as lucky. T.J. Kirkpatrick for NPR hide caption

itoggle caption T.J. Kirkpatrick for NPR

New Jersey Gov. Chris Christie turns to leave a news conference at the Statehouse in Trenton on Tuesday after he announced that he will not run for president in 2012.

Mel Evans/AP hide caption

itoggle caption Mel Evans/AP