In the case of PPP's most recent Florida numbers (McCain up 47-44), here's Tom's take:
John McCain has retaken the lead in Florida after trailing Barack Obama by a small margin last month. The candidates split the independent vote, while McCain receives 84% support from Republicans and Obama gets 76% support from Democrats. The Democrats crossing over to support McCain are disproportionately older white females, an indication that Hillary Clinton's base may not be completely behind Obama in the Sunshine State.
Obama has slipped with Hispanic voters in the last month, leading among them just 48-45 after holding a 51-37 advantage in PPP's previous Florida poll. The numbers show an unusual gender gap, with McCain leading by 11 points among women while trailing by 5 points with men. Last month's results similarly showed Obama doing eight points better with men than women, a trend PPP has not seen in any of its other state by state polling.
Obama has a large lead among young voters, McCain has a big one with senior citizens, and the candidates are virtually tied with those in between.
This is not conventional wisdom regarding Obama's perceived hold on women and Hispanics, and it also raises some intriguing questions about what's going to happen to those numbers when Bob Barr, Ralph Nader, or Cynthia McKinney get added into the questions. Only Zogby is currently using Barr and Nader, placing them at 6% and 2% respectively, but that poll is now going stale (data from late June). Where the PPP poll is interesting is that it shows a significantly larger undecided number (8% as opposed to 5-6% in polls throughout July) than previous estimates.
I'm waiting to see what will happen with the next Zogby poll.