Polls, polls, and more polls! Clinton up by 20 points

The Pennsylvania primary is a week from tomorrow, and there will be many more polls popping up in the coming the hours, I suspect. The candidates have had a very busy weekend, and it will be interesting to see how the Pa. voters react. But first out of the gate is the poll from American Research Group, which has Clinton up by 20 percentage points (click image to enlarge it):

Hillary Clinton leads Barack Obama 48% to 44% among men (45% of likely Democratic primary voters). Among women, Clinton leads 64% to 31%.

Clinton leads 64% to 29% among white voters (82% of likely Democratic primary voters). Obama leads 79% to 18% among African American voters (14% of likely Democratic primary voters).

Clinton leads 52% to 43% among voters age 18 to 49 (50% of likely Democratic primary voters) and Clinton leads 62% to 31% among voters age 50 and older.

10% of all likely Democratic primary voters say they would never vote for Hillary Clinton in the primary and 24% of likely Democratic primary voters say they would never vote for Barack Obama in the primary.

23% of likely Democratic primary voters say that excessive exposure to Obama's advertising is causing them to support Clinton.

What's going on with that last item? People have complained about Clinton "attacking" and running a "negative campaign" in the past, but it looks like Obama's campaign is it's own worst enemy in Pennsylvania.