CREATE TABLE table_18191 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" CLOB, "Result" CLOB, "Candidates" CLOB)

what's the total number of candidates for first elected in 1948 , 1964
SELECT COUNT("Candidates") FROM table_18191 WHERE "First elected" = '1948 , 1964'
SELECT COUNT("Candidates") FROM "table_18191" WHERE "First elected" = '1948 , 1964'