There are a number of possible reasons for the GOP success in blunting what had appeared to be a potent issue for national Democrats. One is that Republicans have sufficiently confused the issue that voters simply can't make sense of it any longer. Bush has adopted much the same tactic. But there was an even more basic problem for Democrats. Health care is precisely the sort of question that voters should not have to sort out on their own.
Most voters lead busy lives.
They don't have the time to get bogged down in such a complex issue. There was a lot of support in the polls for reforming health care in the early 1990s, too. But once people got a look at HillaryCare, they rebelled. Not only did it involve a huge new bureaucracy, HillaryCare looked an awful lot like a government-run HMO with unparalleled power over people's lives. This year's effort to run health care up the electoral flagpole may be more subtle, but voters aren't dumb.