CREATE TABLE "wisconsin" (
  "district" text,
  "incumbent" text,
  "party" text,
  "first_elected" real,
  "results" text,
  "candidates" text
);

Question: Who were the candidates in the district first elected in 1998 whose incumbent ended up being Paul Ryan?
SQL: SELECT "candidates" FROM "wisconsin" WHERE "first_elected"=1998 AND "incumbent"='Paul Ryan';

Question: Who ran in the district elections won by Tom Petri?
SQL: SELECT "candidates" FROM "wisconsin" WHERE "incumbent"='Tom Petri';

Question: When was the first election in the district whose incumbent is Ron Kind?
SQL: SELECT MIN("first_elected") FROM "wisconsin" WHERE "incumbent"='Ron Kind';

Question: What year was the first election in the district whose election now was won by Ron Kind?
SQL: SELECT MIN("first_elected") FROM "wisconsin" WHERE "incumbent"='Ron Kind';