WASHINGTON -- As President Barack Obama and Republican nominee Mitt Romney prepare to face off in their first televised debate Wednesday night, a new batch of polls shows a slight narrowing in Obama's lead in two critical battleground states.
Getting the most attention are three new polls conducted by NBC News, The Wall Street Journal and Marist College that show Obama maintaining a wide lead in Ohio but indicate a slightly tightening race in Florida and Virginia, two must-win states for Romney.
Marist's polls use live interviewers to call random samples of voters on both landline and mobile phones, and its latest surveys were conducted from Sept. 30 to Oct. 1.
In Florida, the new NBC/WSJ/Marist poll gives Obama a one-point edge over Romney (47 to 46 percent). A new Suffolk University poll released on Tuesday gave Obama an only slightly larger, three-point advantage (46 to 43 percent).
Over the last two weeks, nine surveys conducted using a variety of different methods in Florida have all shown Obama with more support than Romney, but the margins on three surveys this week have been collectively closer (1 to 3 percentage points) than those the week before (3 to 9 percentage points).
The HuffPost Pollster tracking model for Florida, based on all public polling, shows Obama's lead over Romney narrowing slightly, from a peak of just of better than three percentage points on Sept. 20 to just over two percentage points Wednesday. Although the model indicates that Obama's lead remains statistically meaningful, the narrower margin moves Florida back into the range HuffPost characterizes as a tossup.
In Virginia, the new NBC/WSJ/Marist poll shows another very close margin for Obama (48 to 46 percent). Another Roanoke College survey released on Tuesday gave Obama a bigger lead (47 to 39 percent), but it had a larger percentage of undecided voters and was conducted over a much longer period (10 days).
When combined with other recent Virginia polls, the Pollster tracking model again indicates a slight tightening of Obama's lead, from four to just under three percentage points. Virginia remains in the "lean Obama" range.
In Ohio, the new NBC/WSJ/Marist survey shows Obama leading by 8 percentage points (51 to 43 percent), a percentage point better than on their last survey conducted just after the Democratic convention.
Two more polls conducted in the last week, a mail-in survey by the Columbus Dispatch and an automated, recorded voice survey by the Democratic Party affiliated firm Public Policy Polling, gave Obama leads of four and nine percentage points respectively.
The Pollster tracking model for Ohio now shows Obama leading Romney by just over six percentage points, roughly the same margin the model has indicated for the past week.
At the national level, the tracking model's estimate of the popular vote, which takes into account both the new national and statewide surveys, also shows no real change in Obama's margin. As of this writing, Obama leads by just over four percentage points nationally, a slightly larger margin than indicated by the model a week ago (the model updates frequently as new polls are added).
As the candidates prepare for their debate, speculation swirls over whether it and the two that follow can shake up the race. Republican pollster and HuffPost Pollster contributor Steve Lombardo argues, for example, that Romney is likely to get a "bounce" from the debates due to outsized expectations for Obama.
But political scientist and HuffPost contributor Thomas Holbrook crunches the past polling numbers and finds that debates rarely shift candidate support by more than a percentage point or two.
Of course, while Obama clearly leads in polling nationwide, the margin is relatively close in comparison to historical averages, so even a small bump for Romney could make the race much closer and more competitive.