As the clock begins to wind down on Election 2008, every event for John McCain is now a must-win event. With Barack Obama starting to break open a comfortable lead in the polls, it will take either a major gaffe on his part or a terrorist walking into a mall in Los Angeles and detonating some kind of nuclear device (and if the Obama campaign hasn’t already gamed that one out and prepared a reaction, they’re even more useless than the John Kerry brain trust in 2004) to stall the momentum. That’s right: McCain is falling so far behind that he can’t even rely on gimmicky stunts or the innate racism of a certain segment of the American electorate to help carry the day. So tonight’s debate is, yes, a must-win event. What should you look for?