There is a famous test, Bell's inequality [2], that specifically rules out local hidden variable interpretations of QM.
Nonlocal hidden variable interpretations, such as De Broglie - Bohm theory [3], are potentially still on the table, however.
It is somewhat ironic that Bell's theorem is sometimes presented in popular media as a general disproof of all hidden variable theories, in a context where locality is taken for granted -- because Bell himself seems to have been partial to nonlocal hidden variable theories. An article by the same Mermin mentioned in the OP is worth a read, on this subject [4].
[1] https://en.wikipedia.org/wiki/Hidden_variable_theory
[2] https://en.wikipedia.org/wiki/Bell%27s_theorem
[3] https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory