From NBC's Ali Weinberg
Here is a further breakdown of the 19 House Democrats who voted for someone other than Nancy Pelosi to lead the caucus.

7 from McCain districts
12 from Obama districts
7 voted for Obama agenda (both cap and trade and health care)
8 voted against Obama agenda
8 won re-election with 55% or more
11 won re-election with less than 55%

North Carolina Rep. Heath Shuler got a higher number of votes (6 out of 7) among Democrats from districts that voted for John McCain in 2008. Seven out of the 12 members from Obama districts voted for someone other than Shuler, or in the case of Georgia Rep. Sanford Bishop voted "present."

Shuler also fared better among Democrats who opposed President Obama's landmark legislative priorities: the "cap and trade" bill (which did not pass the Senate) and the health care reform law. A majority of Democrats who opposed the Obama agenda (7 out of 8) voted for Shuler, versus 2 of the 7 Democrats who voted for both cap and trade and health care.

The majority of Democrats who voted for Shuler received less than 55% of the vote in the 2010 midterms, including California Rep. Jim Costa whose slim margin over Republican challenger Andy Vidak was not confirmed until more than two weeks after the election, and Indiana Rep. Joe Donnelly, who ran several ads, like the one below, touting his distance from the "Washington crowd."