Question: What party did the incumbent from the Illinois 12 district belong to? 
SQL: SELECT "Party" FROM "1-1341707-15" WHERE "District" = 'Illinois 12';

Question: Who was the Democratic incumbent in the Illinois 11 district who was Re-elected? 
SQL: SELECT "Incumbent" FROM "1-1341707-15" WHERE "Party" = 'Democratic' AND "Result" = 'Re-elected' AND "District" = 'Illinois 11';

Question: Which incumbent was first elected in 1964? 
SQL: SELECT "Incumbent" FROM "1-1341707-15" WHERE "First elected" = '1964';

Question: What party did the incumbent from the Illinois 1 district belong to? 
SQL: SELECT "Party" FROM "1-1341707-15" WHERE "District" = 'Illinois 1';