I can't find the info on the wiki. Anyone have any idea, or even an educated guess as to when he was elected? Did he have a vice? I'm not entirely sure how the NCR government works.

Whenever it was NCR first started trickling into Vegas. Kimball got elected to NCR because of his heroism, then when power from Hoover Dam started to flow, his popularity soared. House emerged about seven-eight years prior to the game's beginning. So PROBABLY a little around/after 2274. Maybe 2275-2276. Just an educated guess, not a confirmed statement though.