CREATE TABLE table_78888 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Results" TEXT)

In what year was the republican incumbent from Kentucky 2 district first elected?
SELECT SUM("First elected") FROM table_78888 WHERE "Party" = 'republican' AND "District" = 'kentucky 2'
SELECT SUM("First elected") FROM "table_78888" WHERE "District" = 'kentucky 2' AND "Party" = 'republican'