Tight Race Seen in Swing-State Polls Poll results in three swing states show President Obama and Mitt Romney in tight races in Florida and Virginia, and the president with a six-point advantage in Ohio. In surveys conducted by NBC News/Marist from May 17 to May 20, voters in all three states said the economy outweighed social issues by a wide margin in deciding whom to vote for. And again, in all three states, voters are divided on which candidate would do a better job handling the economy. Ohio voters support Mr. Obama over Mr. Romney by a slim margin, 48 percent to 42 percent. More voters there say Mr. Obama understands the problems of people like themselves, and the president has a 50 percent favorability rating, compared with 39 percent of voters who have a favorable impression of Mr. Romney. Ohio voters are split over which candidate comes closer to their view on social issues, and 48 percent say Mr. Romney would do a better job of reducing the nation's debt, while 38 percent say Mr. Obama would. In the Ohio Senate race, the Democratic incumbent, Sherrod Brown, has a 14-point lead over the Republican challenger, Josh Mandel, the state treasurer, 51 percent to 37 percent. In the Florida poll, 48 percent of registered voters support Mr. Obama, compared to 44 percent for Mr. Romney. Even when Mr. Romney is hypothetically paired with Senator Marco Rubio or former Gov. Jeb Bush as a running mate, voters are still divided. The poll also showed a tight Senate race in Florida, with 46 percent of voters supporting Bill Nelson, the Democrat incumbent, and 42 percent supporting Connie Mack, a Republican congressman. Among registered voters in Virginia, Mr. Obama has 48 percent support compared to 44 percent for Mr. Romney. In the Senate race there, former Gov. Tim Kaine, a Democrat, has a slim lead, 49 percent to 43 percent, over George Allen, the Republican former governor who lost his Senate seat to Jim Webb in 2006. NBC News/Marist College conducted telephone surveys of 1,103 registered voters in Ohio, 1,078 voters in Florida, and 1,076 voters in Virginia, all with a margin of sampling error of plus or minus three percentage points.