U.S. Senator Russ Feingold says personal attacks between the Barack Obama and Hillary Clinton campaigns for the Democratic Presidential nomination could end up helping presumptive Republican nominee John McCain if they continue.

The Wisconsin democrat said during a visit to Wausau Thursday that the attacks need to stop "pretty soon."

He also says that, if the party's "superdelegates" are asked to vote for Obama or Clinton at this summer's national convention, he plans to vote for Obama. But he says he doesn't think superdelegates will cast the deciding votes in determining the nominee in august.