While Barack Obama figures to be an unalloyed asset to down-ballot Illinois Democrats this fall, another statewide politician is threatening to become an equally significant drag on one of the Democrats’ leading congressional recruits.

Democratic Gov. Rod Blagojevich is proving so politically toxic that he has become a central issue in the campaign to succeed retiring Republican Rep. Jerry Weller. Democratic state Senate Majority Leader Debbie Halvorson and Republican concrete magnate Martin Ozinga III are each accusing the other of having closer ties to the two-term governor, one of the country’s most unpopular executives.