Obama had cracked the 50 percent mark on both healthcare and Medicare in Pew's September survey. He now leads Romney 46-43 on Medicare and 47-44 on healthcare.
Despite Romney's gains, though, swing voters still side solidly with Obama. The president has a 21-point advantage on healthcare among voters who say they could still change their minds. Pew's swing voters gave Obama a 17-point edge on Medicare.
Medicare is a central line of attack for the Obama campaign, especially in the pivotal swing state of Florida. Romney and Ryan want to partially privatize Medicare, offering seniors a fixed amount of money to put toward either private insurance or traditional Medicare. Democrats say the plan would "end Medicare as we know it."
Romney and Ryan, meanwhile, have attacked Obama for cutting $716 billion in Medicare payments to doctors, hospitals and private insurance companies in order to pay for his national healthcare reform law.