U.S. President Barack Obama and his Republican challenger, former Massachusetts governor Mitt Romney, are doing a campaign blitz through so-called “swing states” during the final days before Tuesday's election.

After rallies in Wisconsin, Nevada, Colorado, and Ohio Thursday, Mr. Obama plans to spend all day Friday in Ohio — a crucial state for victory for either candidate. Mr. Obama plans to visit Ohio on each of the final four days of the campaign.

Mr. Romney on Friday visits both Wisconsin and Ohio. In West Chester, Ohio, he is expected to join forces with running mate Paul Ryan. The Romney campaign says it expects “nearly 100” governors, senators, mayors, and other officials to attend. In his final days of campaigning, Mr. Romney plans stops in New Hampshire, Iowa, and Colorado.

The candidates are concentrating on the same set of states because they are the so-called “battleground” states that could turn the election one way or the other.

Though disaster relief efforts have won Mr. Obama unusual praise from both Republican New Jersey Governor Chris Christie and independent New York City Mayor Michael Bloomberg, polls show the two candidates are just about tied for popular support.