"It should be a federal requirement if the SCOTUS strikes it down."

By magic?  Or are you thinking Constitutional Amendment?

"Though hopefully we never have such an idiot candidate who refuses like Trump did (and he still wins - sigh)."

I cared far more about Hillary's illegal email server than Trump's tax return.  In fact, tomorrow there's a Federal Court hearing over a Freedom of Information Act lawsuit seeking former Secretary of State Hillary Clinton’s emails during her tenure at the State Department.  The case, Judicial Watch v. U.S. Department of State, was originally filed in May 2015, and will be heard before Judge James Boasberg in Washington D.C. U.S. District Court.

Thank goodness that idiot candidate didn't win, although I realize that a lot of people still voted for her—sigh.