I have myself been critical of President Donald Trump’s refusal to divulge his tax returns, but the bill advanced in the Maryland Senate purporting to make that a requirement for the next presidential ballot in Maryland is partisanship at its most inane. [Sponsors] are here attempting to (1) impose a new qualification on presidential candidates not found in either the U.S. constitution or federal law; (2) do so by means of denying ballot access in their own state, which means by restricting the choices of their own electorate; and (3) do so with the open aim of opposing a single particular candidate.
We may pause for a moment to imagine how this sort of stunt could be pulled by other partisans against other candidates, should it catch on.
No wonder California Gov. Jerry Brown (D) vetoed a similar bill because of the obvious constitutional concerns.
Related: in U.S. Term Limits v. Thornton (1994), a Supreme Court divided 5-4 held that Arkansas could not add to the qualifications for election to Congress enumerated in the Constitution by disqualifying candidates who had already served a set number of terms in office; it also specifically rejected the view that a restriction on ballot access does not act as a bar to office because it leaves open the possibility of running as a write-in.
Note also that the Arizona legislature in 2011, under the influence of “birther” sentiment, passed a measure requiring presidential candidates to provide proof of citizenship in order to get on the state’s ballot. Although natural born citizenship unlike the release of tax returns is of course a genuine constitutional prerequisite for serving as president, the interference with the appropriate distribution of federal-state power, as well as the intent to target one particular candidate, namely birther target and incumbent President Obama, was evident enough that conservative Arizona Gov. Jan Brewer vetoed the measure.