Several recent polls show Obama with an advantage — often a sizeable one — when voters are asked which candidate would do a better job handling healthcare. Obama held that lead even before Romney selected Paul Ryan as his running mate, which elevated the debate over Ryan’s controversial Medicare plan.

Yet polling also shows that the public is deeply divided, and leans negative, on Obama’s signature healthcare law. In the latest tracking poll from the Kaiser Family Foundation, 38 percent had a favorable view of the Affordable Care Act, while 43 percent had an unfavorable view.

Republicans have been assaulting Obama’s healthcare plans almost non-stop for three years, and their attacks have helped stifle public approval of the law. But on the overall issue, Obama is still ahead.

A CNN/ORC poll earlier this week gave Obama a nine-point lead on healthcare (up from just 1 point a month earlier). An Ipsos poll conducted for Reuters put Obama ahead of Romney 51-37 on healthcare, basically unchanged since May.

The New York Times’ last round of swing-state polling, conducted late last month, put Obama up by at least six points on healthcare with voters in Florida, Ohio and Wisconsin.