A survey from Gravis Marketing shows Obama taking 50 percent support in Michigan, over Romney at 46. Obama’s lead in Michigan has grown in recent weeks, and he now has a 9 percentage point advantage over Romney in the Real Clear Politics (RCP) average of polls.

Many analysts have begun shifting Michigan from a toss-up state to one that leans toward Obama.

Obama has a bigger lead in Pennsylvania, according a Morning Call-Muhlenberg College poll. Obama leads Romney 49 percent to 42 in that survey, which is in line with his 8-point advantage in the RCP average.

Virginia, however, remains tight. An American Research Group poll shows Obama with a narrow 49 percent to 47 lead in that state. Obama’s RCP average of polls lead is 3.7 points in Virginia.

Those polls come on the heels of a NBC News-Wall Street Journal-Marist poll released Friday, which showed Obama with narrow leads over Romney in three other swing states: New Hampshire, Nevada and North Carolina.

NBC News-Wall Street Journal-Marist has polled nine swing states in September — Colorado, Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio, Virginia and Wisconsin — and Obama has leads ranging from 2 to 8 points in all of them.

 Those are the bulk of the 12 swing states former President George W. Bush won in 2004 but Obama won in 2008, and they’ll be critical in determining the outcome of the 2012 election.

Obama has also seen a boost in his polling numbers nationally. Obama's lead over Romney was 50 percent to 44 in Wednesday’s Gallup daily tracking poll.