Here's some real arguments from real people explaining their vote for Brown. It was multi-determined from these quotes. But one theme came through:
“I like what Scott Brown stands for and I feel that the Democrats cannot run the country anymore. That too many people that don’t have jobs are going hungry. They’re not taking care of business. They’re not doing their jobs. They’re caught up in this health care thing. I’m saying they’re not taking care of the people that are unemployed.”
Of course the Democrats have extended unemployment insurance, passed a stimulus, bailed out the banks, and revamped a war. But the impression is that they'd been spending so much time on healthcare they couldn't have been doing much else. It was the length of the process in a time of acute economic distress that fanned these fears. Another interviewee sees a divided Congress as better than unified one:
“My feeling is the Democrats have really screwed up since Barack Obama has been in office, and the sooner they lose their majority the better for our country. I think I’m just very disappointed in the direction this country is taking.”
Check it all out. With no exit pols, these focus group sentiments are among the best tools we've got.