What happens if a Presidential candidate dies or must withdraw for some reason during a campaign? Does the spouse step in as has been done sometimes when a Senator dies while in office? That seems absurd. Or, does the VP candidate suddenly become the candidate? Or is there any sort of guideline for it at all? Just trying to think of any scenario that theoretically leads to a really great leader due to twists of fate.
The governor of that state always appoints the replacement. Sometimes that might be the wife, but only if the Governor and the dead senator are of the same party.
You may be thinking about Missouri when a dead man stayed on the ballot and the governor promised to appoint the wife. John Ashcroft stupidly let that go unchallenged for whatever reason, and we suffered immensely because of it.