The Arkansas Secretary of State’s Elections Division website says this:

“Write-in Candidates
Write-in candidates are not allowed in presidential, municipal, or primary elections. [ACA §§7-5-525, 7-8-302, 14-43-202]”

It turns out that none of those election codes referenced actually contain any language referring to write-in candidates for President. Furthermore, the election law regarding write-in candidacy has remain unchanged since at least the early 70s. However, there is legal precedent for Arkansas allowing write-in presidential candidates in at least 1972, for Schmitz/Anderson of the American Party, and 1976, for Eugene McCarthy.

“American Party Loses Bid For Ballot Spot” Northwest Arkansas Times 1972
“Eugene McCarthy”
Northwest Arkansas Times 1976

When asked about this, the legal counsel of the Arkansas Secretary of State’s office was not impressed. It did not seem to matter to him that 1) Arkansas is among only a small handful of states that is currently not allowing write-in Presidential candidates, or 2) that there is a precedent in Arkansas for allowing write-in presidential candidates. The question put to him was: if the law has remained unchanged since 1972, why is it that the Arkansas Secretary of State allowed Schmitz-Anderson to qualify as a write-in Presidential ticket in 1972 in Arkansas, and Eugene McCarthy to qualify as a write-in Presidential candidate in 1976 … and yet now is saying that presidential write-ins are not allowed?

In South Carolina, the prohibition of write-in presidential candidates is actually spelled out clearly in their election laws, but there is nothing of the sort in Arkansas. There is in fact clear precedent, and a strong national context for allowing Presidential write-ins in Arkansas, but they are not being allowed.