The Weekly Standard bases this conclusion on the IWV poll of independent voters:
Nearly half (48 percent) of all independent voters said that even if a candidate otherwise held perfect views (in the eyes of the voter) — even if they “agreed with him on all other issues” (italics added) — they still couldn’t vote for him “if [they] disagreed with him on health care reform.” (Another 13 percent weren’t sure whether they could abide such a costly error in judgment or not.)
And what must the candidate’s position on health-care reform be? For 83 percent of the respondents who said their vote would hang in the balance, the candidate must oppose Obamacare. So, according to the survey, if you support Obamacare, you’ve just lost 40 percent (83 percent of 48 percent) of the independent vote — before any other issue is even addressed.