A week ago, the GWU Battleground poll (pdf) showed Obama with a 13-point lead over McCain (53-40). Today, after a week of steady narrowing, that lead is down to one point (48-47).
If the undecided 6% breaks toward McCain (as the cable news heads assure us they will), and/or if Obama's young-skewing constituency can be trusted to show up in fewer numbers than McCain's older electorate, and/or if the Bradley effect on display throughout the Democratic primary exists at all (or - for the racially sensitive - let's say "if Obama continues to systematically overpoll, for whatever reason, compared with his actual vote share"), and/or if the trend is ongoing, then this is a very McCain-friendly data point.
The poll's survey window is 7 days wide, so even if the trend has recently stopped, this latest reading wouldn’t yet capture the entirety of McCain's gains.
Hat Tip: Stop the ACLU