Those factors were each cited by 27 percent of respondents in answer to an open question asked by Pew. Eight percent each say the proposals haven't been explained well enough and that the current system works, while an overhauled one would not. Six percent like the health care they already have and 5 percent fear the program won't be fair to all.

The poll also reported that opposition to health reform declined slightly this month: 44 percent opposed it, 38 percent were in favor and 18 percent expressed no opinion. Last month, 46 percent opposed it, 39 percent favored it, and 15 percent expressed no opinion.

Meanwhile, a Gallup poll conducted Nov. 5-8 found that 38 percent of Americans rate health care coverage in the U.S. as good or excellent, the highest number since Gallup began asking the question in 2002.