(CBS News) -- A series of polls released today and over the weekend show the presidential contest remains close but suggest President Obama may have an edge over Mitt Romney on the issue of who would best handle Medicare.
A Gallup swing state poll released Monday shows that voters in 12 key states trust Mr. Obama over Romney to address issues facing Medicare, 50 percent to 44 percent.
While always an important election issue, the future of Medicare became a more prominent campaign matter when Romney chose Rep. Paul Ryan as his running mate. The House Budget Committee chairman authored the House GOP's plan to overhaul the popular government health care program for seniors, which would give seniors the choice of using a voucher to purchase private insurance. Still, the Gallup poll shows swing state voters are more likely to believe (51 percent to 44 percent) that Mr. Obama's campaign has a specific plan for Medicare than to believe that the Romney campaign does.
The Gallup poll, conducted Sept. 11-17, surveyed voters in Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, Virginia, and Wisconsin.
A Reuters/Ipsos poll released Monday shows that Mr. Obama is gaining ground among Americans who are at least 60 years old (Medicare recipients must be at least 65 years old). While Romney once had a 20-point advantage among that age group, the Reuters poll now shows Mr. Obama trailing by fewer than four points.
Reuters reports, "Romney's double-digit advantages among older voters on the issues of healthcare and Medicare - the nation's health insurance program for those over 65 and the disabled - also have evaporated, and Obama has begun to build an advantage in both areas."
Another national poll, however, shows Romney holding onto his strong lead among seniors. The Politico /George Washington University poll, conducted Sept. 16 - 20, shows Romney leading among voters 65 and older, 58 percent to 38 percent.
Voters overall say Mr. Obama would do a better job handling Medicare, according to the Politico poll, 52 percent to 43 percent. Aside from the federal budget and spending, Mr. Obama ties or has an edge over Romney on who is best to handle every major issue.
The poll shows Mr. Obama leading Romney 50 percent to 47 percent among national voters, though Romney has a two-point edge among independents.
A Miami Herald/Tampa Bay Times poll shows that voters in Florida are nearly split over who they trust to keep Medicare financially stable, with 49 percent choosing Mr. Obama and 47 percent choosing Romney. Voters in the battleground state are also split over who to support -- 48 percent say they're backing Mr. Obama, while Romney wins 47 percent support. Independents in Florida back Mr. Obama by a margin of 11 percent.
In the Buckeye State, the Ohio Newspaper Poll shows Mr. Obama with a lead of 51 percent to Romney's 46 percent among likely voters.
In the swing state of Pennsylvania, the latest Susquehanna Polling & Research survey shows Mr. Obama leading 47 percent to Romney's 45 percent.