Earlier this year, Joy Padgett, an Ohio state senator and the Republicans' top choice to succeed Ney, ran unsuccessfully for lieutenant governor. But the state's sore-loser law, which prevents a candidate from entering one primary after losing another in the same election cycle, could complicate her bid.

Ney abandoned his re-election campaign this week amid concern from top Republicans that his increasingly close race could complicate party efforts to maintain control of the House. Ney, enmeshed in the Jack Abramoff lobbying investigation for more than a year, and House Majority Leader John Boehner, also of Ohio, called on Padgett to replace Ney.

But strategists from both parties were uncertain early this week whether she would qualify for the ballot. "It's unclear at this point who that Republican nominee would be," said Carl Forti, spokesman for the National Republican Congressional Committee. Added Brian Rothenberg, communications director for the Ohio Democratic Party: "You can't just lose the primary and run for a different [office]. You can't go into a backroom and choose somebody and ignore the laws in the district."

--Silla Brush