Answer: Pretty soon, potentially. Via CNN, a rundown of when the polls in various battleground states close (all times ET):

7 p.m. Indiana, Virginia
7:30 p.m. Ohio, North Carolina
8 p.m. Pennsylvania, Florida, Missouri
9 p.m. Colorado, New Mexico, Arizona, North Dakota
10 p.m. Nevada, Montana

I didn’t include Iowa because it’s not a battleground anymore, assuming it ever was, but that’s also a 10 p.m. close for what it’s worth.

The line is there because none of the states below it matter much unless Maverick’s come close to running the table in the states above it. Play around with CNN’s electoral map and you’ll see what I mean. Give him every last state from 9 p.m. on, then try to figure out how many pre-9 p.m. states he can lose and still reach 270. Unless I missed something, it boils down to this:

1. He can afford to lose any single state above the line, no matter which it is, so long as he wins all the others.

2. He can afford to lose any combination of Indiana, Virginia, and Missouri (but not all three), so long as he wins every other state above the line.

3. Under no circumstances can he afford to lose a combination of Pennsylvania, Ohio, and Virginia. Two out of three is a must, plus every other state above the line. McCain currently trails in all three by anywhere from four to seven points, per the RCP state averages. (Fun fact: Given my assumptions, if Maverick wins Pennsylvania and Virginia, Obama wins Ohio, and they split Indiana and Missouri, it’s 269-269.)

What this means, given The One’s lead, is that each hour on Tuesday night operates almost like an elimination game. If McCain wins Indiana and Virginia, he survives and advances to the next round against Ohio and North Carolina. If he wins both of those, he moves on to the eastern regional championship in Pennsylvania and Florida. And if he wins both of those, he heads west for the Final Four Six. As I say, he can technically afford to lose one or two states early (depending upon which ones they are), but the bellwether omens will be grim if he’s dropped any battlegrounds before 8 p.m. And again, to win the election he’d almost certainly then have to win all six of those western states. If you believe PPP, not only does The One lead big in Colorado and New Mexico, but a majority of voters have already cast their ballots. Assuming that’s true, McCain’s margin of error above the line is virtually zero.

Needless to say, if both Indiana and Virginia are called for Obama, commence drinking immediately. Here’s the latest battleground snapshot from Mason-Dixon. Every vote counts, swing-staters.