I've noticed a major factor separating these polls is how they report Obama's support in major cities and their surrounding suburban tier cities.
For example, SUSA has Clinton ahead of Obama in SE Pennsylvania (Philly + 'burbs) while the polls that place Obama within single digits show him ahead in that region, typically be a considerable margin (10+ points). These polls are more or less in agreement with how he'll perform in the rest of the state.
Ultimately on the 22nd the suburbs of Philadelphia will decide whether its a Clinton victory or a Clinton blowout.
This is a good point. It's difficult to tell simply by looking at polls that one is more accurate than the other. You have to look below the hood . . . check the engine, kick the tires. And if you find something that raises a red flag, then you may be on to something.
Because ultimately the poll numbers depend on (1) questions asked, (2) how hard undecideds are pushed, and (3) the cross tabs, any one of these can affect one company's projections for a particular part of a state versus another.
I guess, as you say, we'll find out on 4/22.
