CREATE TABLE table_78703 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Results" TEXT)

What is the First Elected date of the Republican with Results of retired republican hold?
SELECT MIN("First elected") FROM table_78703 WHERE "Party" = 'republican' AND "Results" = 'retired republican hold'
SELECT MIN("First elected") FROM "table_78703" WHERE "Party" = 'republican' AND "Results" = 'retired republican hold'