Post polls: Obama has lead in Ohio, edge in Fla., hampering Romney path to victory President Obama is threatening Mitt Romney's best route to victory in the electoral college, grabbing a significant lead over his Republican challenger in Ohio and a slender edge in Florida, according to two new polls by The Washington Post. Democratic candidates have even larger leads in the Senate races in those two states, according to the polls. Together, the results suggest that with six weeks left until the election, Democrats hold significant advantages in some important battlegrounds. Florida and Ohio battleground polls. Explanations vary as to why. Melinda Henneberger In the presidential race, Obama is ahead of Romney in Ohio by 52 percent to 44 percent among likely voters. In Florida, the president leads 51 percent to 47 percent, a numerical edge but not a statistically significant one. Romney began a two-day bus tour of Ohio on Tuesday afternoon in an effort to build enthusiasm for his candidacy and narrow the gap with Obama. The trip will take him from Dayton to Columbus to Toledo before he departs for Virginia, another key battleground where he is behind in public polls. Rich Beeson, Romney's political director, brushed aside the public polls of Ohio, telling reporters traveling with the candidate Tuesday that the campaign is making strategic decisions based on its internal surveys and research and remains confident about the outcome. At his rally north of Dayton, Romney stressed that there are big philosophical differences between him and Obama, saying that the president's approach is "foreign to anything this country has ever known." Campaign advisers said they will seek to deliver a clear and consistent message outlining Romney's policy priorities as a way to draw contrasts with the incumbent. Romney has only a few days to drive that message before both campaigns are consumed by the presidential debates. The three presidential and one vice-presidential debate will offer Romney and his running mate, Rep. Paul Ryan (Wis.), their best chance to change the dynamics of the race and put Obama on the defensive. The first presidential debate will be held Oct. 3 in Denver. With Romney lagging, Republicans face additional challenges down-ballot in the same battleground states. In the new Post surveys, Democratic Sen. Sherrod Brown of Ohio holds a substantial lead over Republican Josh Mandel, giving Democrats some breathing room in a race in which outside groups have put nearly $20 million toward defeating the incumbent. Brown leads Mandel 53 percent to 41 percent among likely voters. In Florida's Senate race, incumbent Bill Nelson (D) holds a 14-point advantage over Rep. Connie Mack (R), leading 54 percent to 40 percent among likely voters. The new numbers come one week after a Post poll in Virginia showed Obama with a clear lead there. More than half of all the money spent in the campaign has focused on these three states, and many analysts say Romney has to win two of the three to capture the White House. The past few weeks have been difficult for the Romney campaign, and the nominee's advisers vowed to hit the reset button this week. But with the first debate scheduled for next week, Romney is under new pressure to refocus his campaign.