The effect was decidedly minor. According to PredictWise, which aggregates Intrade and other online betting markets, Obama has gone from a 64.6 percent to a 65.2 percent favorite to win. There's only so much a vice presidential debate can do.
That's better than nothing, although critics of such markets -- which essentially put a percentage on conventional wisdom -- have pointed out that they are wrong as often as the conventional wisdom is wrong. A lot, in other words.
Overall, the markets think Obama's odds have sharply slid over the last two weeks, from about 80 percent before his much-derided debate performance.