Any challange will come not from the candidate himself but from voters arguing they are being disenfranchised. And they would have a valid point.
We could be treading into dangerous territory when we write reactionary laws that would limit who we can vote for to only those candidates who have been "pre-approved" by the State. This is no different than the style of "democracy" practiced in places like Iran. And if conservatives don't think such a law will come back and bite us in the tail, we need to think again.
I don’t think it’s a problem about voters being disenfranchised because of requirements to follow for how a candidate is supposed to get on the ballot...
For example, there’s a “date” requirement. If the candidate does not follow the required date to file, they’re not on the ballot. But, no one is going to say that these voters are disenfranchised, by the state (because of their date requirement) if the candidate fails to meet it.
And also, another similar example (although not applying directly to the Presidential candidate) is a residency requirement for a particular office (in the state). With that, if the candidate does not meet the state law which requires a certain residency for that candidate to be able to be on the ballot (or even qualified to run) — the voters cannot put up a challenge saying that because the state required a certain residency that they were disenfranchised because of the state law.
There’s just too many examples of these types of things where (as you were saying) that a bunch of voters could say that they were disenfranchised because the state had a law which prevented the candidate from being on the ballot... LOL...