This is more of an aside, but given that Clinton lost by so little, _very many things_ caused her to lose. Because of such a small margin, for almost any X: "X had little effect" and "X caused Clinton to lose" can be simultaneously true.
If you lose by only one vote, then every vote caused you to lose.
(Of course if you're running a campaign, going after things that are bigger issues is more useful, but when we're talking about billion dollar operations, you can go after everything in theory)
She did lose by quite a bit, though. 74 electoral votes out of 538. And that’s after rigging the primaries and spending twice as much as Trump did. Not even 1.2 billion could make this albatross fly.
It sounds like a lot, but it ends up not being much. It was, of course, 40k votes over 3 states. But most Presidential elections the winner carries more than 320 electoral votes. Bush 2 had pretty slim margins, of course. Before that, you need to go back to Carter to get 297 electoral votes.
It's not the tightest margin, but it's among the lowest margin of victories in the electoral college. Not that it matters, because you either win or lose. And we all know the rules of the game before we start playing
Electoral votes are a terrible way to measure the closeness of an election though. You could win every state by a single vote, and according to the electoral votes it would look like a blowout, but in reality it would have been the closest election in modern history.
If you lose by only one vote, then every vote caused you to lose.
(Of course if you're running a campaign, going after things that are bigger issues is more useful, but when we're talking about billion dollar operations, you can go after everything in theory)