Filling the Straight

Several pundits have suggested that McCain's attempt to win Pennsylvania, and thereby the election, is the electoral equivalent of the losing poker play, trying to "fill the inside straight".

It's actually worse than that: McCain is trying to get a straight in draw poker with the 4, 6, 7, drawing two cards. Getting the unlikely "5"--Pennsylvania--would still require him to get a 3 or 8 to win.

Here's why, and starting from our 291-200, with 47 (FL/OH) toss-up scenario. McCain would have to do all the following, starting from the most likely:
1) Win all those states like MT, GA, ND that he should be winning and is narrowly ahead.
2) Win those three big perennially-red states that I call "leaning McCain"--IN, NC, and MO--but are polling about even.
3) Win both Ohio and Florida, the two (large) states that look like true toss-ups to me still today. They are historically close, both parties have fully mobilized, and the polls are consistently close this time around, too. Both have shown narrow leads for Obama in recent days, Ohio's maybe a tad larger, but somewhat more unreliably.
4) Win Pennsylvania. The polling gap has closed from safe Obama to slightly nervous Obama--a lead of about 7 points, just about the margin of error in these polls.

All four of these successes would leave McCain at 268 Electoral Votes, to Obama's 270. McCain would still need:
5) To steal a state which has a lead for Obama larger than the margin of error. Most likely candidates would be NV, VA, CO, or NH.

If it were just 5), this would hardly be impossible--probably a 25% chance for one of them. However, winning Pennsylvania is about like drawing a '5'--a 1-in-13 chance. Combined, a 1-in-52 chance, about 2%--it makes the 9-10% odds for McCain on Rasmussen or CNN Markets look way overstated.

As for the cards, getting a '5' and a '3' or '8' (independent of the cards already dealt out) would be a 1/13 * 2/13 * 2 (cause the order could be either). That's 4-in-169, or about 2.4%.