user: Question: Which incumbent's democratic candidate was Mike Carroll?
Columns: ['District', 'Incumbent', '2008 Status', 'Democratic', 'Republican']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Steve Chabot', 'Re-election', 'Steve Driehaus', 'Steve Chabot']
SQL:

assistant: SELECT "Incumbent" FROM "Table" WHERE "Democratic" = 'Mike Carroll';