The newspaper said interviews with close to a dozen unnamed congressional Democrats on the ballot this year show a lack of enthusiasm for Obama's help -- something that reflects the president's 46 percent approval rating in the polls.
The Democrats give a variety of reasons, the newspaper said: The president's busy schedule and a long-term practice of not bringing in outside campaigners.
The uncertainty over Obama was seen in Virginia last year, Politico said. Democratic gubernatorial candidate Creigh Deeds at first rejected Obama's help, then embraced it when polls in the final weeks of the campaign showed him far behind.
Politico said uncertainty about Obama has now evolved into a feeling among centrist Democrats that they would be better off if he didn't campaign on their behalf.