dr. zelizer events overtake a presidency? >> that's what they are about. they are responding to crises and responding to the way in which events unhold. rarely does a president campaign 10 issues go in the white house and focus on those ten years and leave. something has got to happen. and i think the best presidents like lyndon johnson, for example, fdr or ronald reagan knew that and ronald reagan and gorbachev wasn't what he could predict and how he approaches the soviet union and the fact how he remembers ronald reagan and then lyndon johnson was vietnam. i mean, the way that overtook his presidency was something he didn't expect in '63 and '64. that's what being a president is about. and in some ways that's what we measure. that's one of the things we look for. how do they respond when those events happen? when those shifts take place. >> and tevi troy, you're nodding your head. >> i want to remark both on this question the political savvy and whether there's a checklist. and president bush, i think, showed his political savvy both in being elected twi