Nixon might have gone to China a time or two, but Arnold’s practically taken up residence. His persona has left him essentially invincible on questions of toughness, and he’s used the freedom for pretty progressive ends. It wasn’t long ago that he signed into law a needle-exchange program that Gray Davis, afraid of being demagogued by the right, vetoed thrice. Now he’s reforming California’s shameful prisons by shunning the all-powerful prison guards union and forcing a move towards rehabilitation. Next up? Redistricting.

Ezra Klein is a former Prospect writer and current editor-in-chief at Vox. His work has appeared in the LA Times, The Guardian, The Washington Monthly, The New Republic, Slate, and The Columbia Journalism Review. He’s been a commentator on MSNBC, CNN, NPR, and more.