1. With a same party incumbent there will be those that have pet peeves about the incumbent which will be associated with the new candidate. Some of those folks will take a share the blame tact and may either not vote or vote for an opponent. (Voting third party isn't as bad as voting Republican but still we lose votes.)

2. When an incumbent runs for reelection, they have advantages of being a known quantity.

3. There may have been those among us who just refused to vote for a woman. I find that hard to believe in this century and see it as completely reprehensible but still a possibility.

4. There are those who weren't happy with their candidate not being selected. This is a big point. The ugly fact is that nothing unites people better than a common enemy. All the negatives about DWS, the email crap and even going back to folks who just didn't/don't like Bill all may have played a part in suppressing if not turning votes.

5. Having local folks that get votes out is biggest answer.