CREATE TABLE "table1_1341707_15" (
  "district" text,
  "incumbent" text,
  "party" text,
  "first_elected" text,
  "result" text,
  "candidates" text
);

Question: What party did the incumbent from the Illinois 12 district belong to? 
SQL: SELECT "party" FROM "table1_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 "table1_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 "table1_1341707_15" WHERE "first_elected"='1964';

Question: What party did the incumbent from the Illinois 1 district belong to? 
SQL: SELECT "party" FROM "table1_1341707_15" WHERE "district"='Illinois 1';