And the winner by a nose is...shut up about Obamacare!
A slight majority of registered voters, 51 percent, are tired of hearing congressional candidates talk about Obamacare, and want them to instead talk about things like jobs, a new Kaiser Health Tracking Poll revealed Friday. Just 43 percent want to continue listening to debate about the health-care reform law.
The poll also underscored how entrenched the law is likely to remain in the U.S., despite its relative unpopularity.
Although 45 percent of the public has an unfavorable view of Obamacare-7 percent higher than people with favorable views- 59 percent favor improving the law over repealing and replacing it. Just 34 percent said they want the 4-year-old law scrapped.
"I think there may be a sense that this law's been on the books a long time now, so for some people who view it unfavorably, they'd rather improve what's there instead of taking it out," said Liz Hamel, director of the Kaiser Family Foundation's public opinion and survey research unit.
Read More 7 in 10 say Obamacare had bad or zero impact on US
Public ambivalence over the law presents potential pitfalls for this year's congressional candidates; 3 in 10 voters polled by Kaiser said they would vote "only for a candidate who shares your views on the health-care law."
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.
Read More Obamacare hasn't cured drugstore sticker shock
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.
The partisan divide continued when the poll asked people whether the Affordable Care Act had helped or hurt them and their families.
Overall, 60 percent of respondents said there was no impact from the ACA. Twenty-four percent said Obamacare had hurt them, and 14 percent said it had helped.
However, Democrats were three times as likely to say they were helped by the law as opposed to harmed. Twenty-six percent of Democrats said the law was a boon to their lives, compared to 8 percent who said it was a bane.
Read More Retire early because of Obamacare? Think again...
Republicans, however, were more than seven times as likely to say the law hurt them. Thirty-five percent of Republicans said they law had a negative effect on their lives, compared to just 5 percent who said it had a positive effect.
Among independents, 27 percent said Obamacare had hurt them, while 11 percent said it had helped.
Republicans were also much more likely than Democrats or independents to report personally knowing someone who had lost their health insurance because of Obamacare, and lost their jobs or had hours cut because of it. Thirty-four percent of Republicans said they knew someone who was the victim of either situation.
Democrats, on the other hand, were much more apt to report knowing someone who was able to get health insurance because of Obamacare. Forty-six percent of Democrats said they knew such a person, while just 19 percent of Republicans did.
-By CNBC's Dan Mangan.