You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: FEDERAL PUBLIC SERVANTS 
Clue: With 7 years' service, this man who resigned in June 2004 had the longest tenure in his position in over 4 decades
george tenet

Category: PRESIDENTS 
Clue: 2 of the 3 successive presidents who were Republicans, born in Ohio & generals in the Union army
ulysses s. grant, rutherford b. hayes & james a. garfield

Category: BRITISH WORD ORIGINS 
Clue: These political party names began as negative terms for the 2 factions warring over the 1678 Meal-Tub Plot

tories & whigs