Who were the candidates in the district whose incumbent is Joe Waggonner?
{'header': ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates'], 'page_title': 'United States House of Representatives elections, 1966', 'page_id': '', 'types': ['text', 'text', 'text', 'real', 'text', 'text'], 'id': '1-1341843-19', 'section_title': '', 'caption': '', 'rows': [['Louisiana 1', 'F. Edward Hebert', 'Democratic', '1940', 'Re-elected', 'F. Edward Hebert (D) Unopposed'], ['Louisiana 2', 'Hale Boggs', 'Democratic', '1946', 'Re-elected', 'Hale Boggs (D) 68.6% Leonard L. Limes (R) 31.4%'], ['Louisiana 3', 'Edwin E. Willis', 'Democratic', '1948', 'Re-elected', 'Edwin E. Willis (D) 59.7% Hall M. Lyons (R) 40.3%'], ['Louisiana 4', 'Joe Waggonner', 'Democratic', '1961', 'Re-elected', 'Joe Waggonner (D) Unopposed'], ['Louisiana 5', 'Otto Passman', 'Democratic', '1946', 'Re-elected', 'Otto Passman (D) Unopposed'], ['Louisiana 6', 'James H. Morrison', 'Democratic', '1942', 'Lost renomination Democratic hold', 'John Rarick (D) 76.6% Crayton G. Hall (R) 23.4%'], ['Louisiana 7', 'Edwin Edwards', 'Democratic', '1965', 'Re-elected', 'Edwin Edwards (D) Unopposed']], 'name': 'table_1341843_19'}