user: Question: Who is the Incumbent that has a District of Ohio 13 in Democratic Party?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Ohio 1', 'George H. Pendleton', 'Democratic', 1856.0, 'Retired Republican gain']
SQL:

assistant: SELECT "Incumbent" FROM "Table" WHERE "District" = 'Ohio 13';