Just a quick thought, for what it's worth, about the polls as we head into the March 4 home-stretch: I spent the last hour or so looking over crosstabs for the all recent Texas and Ohio polls, except the ones by pollsters I don't really trust (basically Zogby and Rasmussen). My overall conclusion, based mostly on a gut feeling about what various demographic groups will do (known in any other context as a "stereotype") is that the Ohio polls slightly overstate Hillary's lead and the Texas polls slightly overstate Obama's (which is slight to begin with).*
In Ohio, the recent polls show Hillary with a 5- to 8-point lead. They consistently show Obama losing white voters by 15-20 points, which sounds about right to me (though he could certainly narrow the gap in the next few days); they also show him consistently attracting between 70 and 80 percent of black voters, which seems a little low to me. I suspect it'll be closer to 85 percent on Election Day without any change in the underlying dynamic of the race, which means adding another 1 to 2 points onto his overall vote-share. So I'd say Obama is more like 3- to 5-points down.
In Texas, the recent polls show Obama with a 3- to 7-point lead. They show him winning 85 to 90 percent of the black vote, which strikes me as plausible. But they tend to show him doing surprisingly well among either Hispanics (down only 10-15 points) or whites (anywhere from up 3 to down 13). I suspect he's looking at more like a 25-point loss among Hispanics, and a 15-20 point loss (call it 17) among whites. If you put that together with an 85-15 win among blacks, and you accept ARG's turnout figures (just for the sake of argument), you end up with 50.5 to 49.5 Clinton advantage--that is, dead even.
As with Ohio, keep in mind that this is where I think things stand now--or where they'd finish without any changes in the race. Obviously a slight bump or dip for one of the candidates among one or more of these groups would send things in one direction or the other.
P.S. The campaigns normally send out their schedules 2-3 days in advance. But, as of right now--6:29 PM on Friday--I only know their schedules through tomorrow afternoon. I'm guessing that reflects the closeness of the Texas and Ohio races. The campaigns don't want to commit to a day in either state until they know as much as possible about where they stand.
*Please no comments quibbling with specific figures. This is basically a qualitative, back-of-the-envelope exercise intended to give a general sense of where I think things stand. If, on the other hand, you think I'm way, way off on something, by all means let me know.
Update, Saturday, 12:33 PM: Both Hillary and Obama will be spending tomorrow in Ohio. I suspect they're both seeing a tight-ish race there in their internal polls...