CREATE TABLE table_79148 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Results" TEXT)

Which district has a Democratic incumbent that was first elected before 1996?
SELECT "District" FROM table_79148 WHERE "Party" = 'democratic' AND "First elected" < '1996'
SELECT "District" FROM "table_79148" WHERE "First elected" < '1996' AND "Party" = 'democratic'