In Democratic caucus meetings throughout 2009 and this year, White House senior adviser David Axelrod repeatedly made the case that wavering Democrats would be tarred by Republicans with the president’s agenda whether they liked it or not. So, he argued, they might as well vote with the White House.

But resistance to the agenda is rewarding some House Democrats as the midterm elections approach. Mr. Bright from Alabama voted against the president on health care, climate change, the stimulus act and Wall Street regulation—and in one of the most conservative districts represented by any Democrat, he is strongly in the running.

Rep. Larry Kissell squeaked into office on the Obama wave in North Carolina with the backing of liberal Internet activists. Now, he is touting his votes against the health overhaul and the climate bill that would cap emissions of greenhouse gases, and is sporting a double-digit polling lead.

In a conservative Mississippi House district, Democratic Rep. Travis Childers stunned the GOP by winning a special election in May 2008. Republicans thought it was a fluke. But after opposing the Democratic health-care, climate-change and financial-regulation bills, Rep. Childers is running strongly again.