Another 52 percent said they would consider a candidate's position on the law "as just one of many important factors," according to the poll, which questioned 1,505 adults, and which had a margin of sampling error of plus or minus 3 percent.
Last fall, many Democrats were dismayed about their election prospects and Republicans were gleeful because of the botched launch of the federal Obamacare exchange HealthCare.gov. But with the repair of that marketplace, and the enrollment by this month of 8 million people in Obamacare insurance plans, some Democratic incumbents in tight races are embracing the law in their campaigns.
While about half the registered voters polled by Kaiser said they had heard enough debate about Obamacare already this campaign season, individual voters' opinion on that question was closely linked to their political affiliation.
Seven in 10 Democratic voters, who overwhelmingly favor the law, said congressional candidates should talk about something besides Obamacare, which was enacted by a Democratic-controlled Congress at the behest of a Democratic president.
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But 6 in 10 Republicans, who overwhelmingly oppose Obamacare, said they favor continued political debate over the law as this fall's midterm elections approach.
"That helps you understand why so many Republicans are talking about it in their campaigns and advertising," said Hamel.