Does USA have something like an election commision? If a candidate or their representatives publish false information in the election season and any citizen complains about it, the election commision can try the candidate and perhaps even ban the candidate from participating in the elections. The onus is directly on the liar to not lie
So we'd have elections with no candidates at all. Or, more realistically, we'd have ones that have opinions matching opinions of those people who sit on the commission. Nice system, though it's not clear why bother with elections then at all - we just let the commission - after all, people who know all the truth must know how to select good people who tell the truth? - to choose suitable candidates. Elections where candidates that the commission doesn't like are excluded are no elections anyway - you can look at Russia how it works, they have "elections" exactly like that - people not approved by Kremlin largely just are excluded from participation, so nobody can vote for them.