BACK AGAIN: As Vice President Joseph R. Biden Jr. (right) looks on, President Obama addresses a Sunday rally at Cleveland State University. Mr. Obama has been to the swing state of Ohio on behalf of the Democratic nominees for governor and Senate a dozen times. (Associated Press)

BACK AGAIN: As Vice President Joseph R. Biden Jr. (right) looks on, President Obama addresses a Sunday rally at Cleveland State University. Mr. Obama has been to the swing state of Ohio on behalf of the Democratic nominees for governor and Senate a dozen times. (Associated Press)