The Secreatary of State is charged with ensuring the eligibility of candidates on ballots in most states. The Sec. of States office in my state of Washington has told me (twice) that they do not perform these checks on candidates for POTUS. That’s a violation of the statutory requirement that they do so. I plan on sending them a nicely worded registered letter insisting that they institute a procedure for ensuring that candidates are vetted for ALL offices, as the law requires.
That's because candidates for POTUS do not appear on the ballot anywhere in the United States.