user: Question: Incumbent John Sullivan has what as biggest first elected?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Results']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Oklahoma 1', 'John Sullivan', 'Republican', 2002.0, 'Re-elected']
SQL:

assistant: SELECT MAX("First elected") FROM "Table" WHERE "Incumbent" = 'John Sullivan';