Anyway, there’s a pattern here: Coakley carries districts where Obama got 65% or more of the vote and runs essentially even in the district where he got 64%, and Scott Brown runs ahead in districts where Obama got less than 64% of the vote.
Let’s extrapolate those numbers to the nation as a whole and assume that a district that voted 64% or more for Obama is safe for Democrats even under the most dire of circumstances. How many such districts are there? Answer, according to this source: 103. The other 332 districts voted 63% or less for Obama. Interestingly, there are more 64%+ Obama districts in the West (36) than in the East (27) and more in the South (21) than in the Midwest (19). --Michael Barone
Hooboy. Look at the vote percentages at this site (scroll a bit) and you find Obey and Kagen are at least theoretically in trouble.