Table schema:
CREATE TABLE table_1342149_42 (party VARCHAR, candidates VARCHAR)

Question: How many parties match the canididates listed as howard baker, sr. (r) 68.9% boyd w. cox (d) 31.1%?
SQL: SELECT COUNT(party) FROM table_1342149_42 WHERE candidates = "Howard Baker, Sr. (R) 68.9% Boyd W. Cox (D) 31.1%"