[['state (class)', 'vacator', 'reason for change', 'successor', 'date of successors formal installation'], ['tennessee (2)', 'estes kefauver (d)', 'died august 10 , 1963', 'herbert s walters (d)', 'august 20 , 1963'], ['california (1)', 'clair engle (d)', 'died july 30 , 1964', 'pierre salinger (d)', 'august 4 , 1964'], ['south carolina (2)', 'strom thurmond (d)', 'changed political parties', 'strom thurmond (r)', 'september 16 , 1964'], ['new mexico (1)', 'edwin l mechem (r)', 'resigned november 3 , 1964', 'joseph montoya (d)', 'november 4 , 1964'], ['oklahoma (2)', 'j howard edmondson (d)', 'successor elected november 3 , 1964', 'fred r harris (d)', 'november 4 , 1964'], ['tennessee (2)', 'herbert s walters (d)', 'successor elected november 3 , 1964', 'ross bass (d)', 'november 4 , 1964']]
Tennessee Change 2 time in 2 year
[ENT] [ENT] 2 time in 2 year