Obama Crosses the 50 Percent Threshold

From Jonathan Singer's post here on the tracking polls.

Here are today's numbers:

Note that this is the first time since the four tracking polls have been watching the race that Barack Obama has topped 50 percent in his four-poll average. . . .

Note, too, that in the single-day sample of 359 likely voters . . ., which occurred in the day after the Vice Presidential debate, John McCain actually slipped below the 40 percent marker, coming in with an unimpressive 39 percent showing. The movement from the previous day when McCain was at 40 percent was not significant. Nevertheless, it cannot be very encouraging to Republicans to be polling in the 30s exactly one month out from election day. . . .