user: Question: Who was the Democratic incumbent in the Illinois 11 district who was Re-elected? 
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Illinois 1', 'Ralph H. Metcalfe', 'Democratic', '1970', 'Re-elected', 'Ralph H. Metcalfe (D) 91.4% Louis Coggs (R) 8.6%']
SQL:

assistant: SELECT "Incumbent" FROM "Table" WHERE "Party" = 'Democratic' AND "Result" = 'Re-elected' AND "District" = 'Illinois 11';