Four out of every five House members who didn’t side with their party on the health care bill represent districts that voted for the opposite party’s presidential nominee in the 2008 election.

The party-buckers on the 220-215 vote on Saturday night included 39 Democrats who voted against the bill. Of them, 31 represent districts that voted for John McCain over Barack Obama. Republicans are targeting many of them for defeat in the 2010 election. Of the other eight, three are serving their first terms in districts in which they defeated or succeeded Republicans in the 2008 election.

Eighteen Democrats from McCain-voting districts backed the bill. Among this subset, seven-term Rep. Marion Berry of Arkansas represents the most pro-McCain district (59 percent). He’s more politically secure than other “McCain Democrats” who voted for the bill, including first-term Rep. Tom Perriello of Virginia and second-term Rep. Zack Space of Ohio.