When working on this answer, I tried to figure out when the filing deadlines were for each state’s presidential primary, and my searches keep turning up contradictory information! Ballotpedia lists seven states as having deadlines in 2019, which was referenced by fivethirtyeight.com, but since this other list on Ballotpedia lists Iowa’s primary as being in June (it’s the first one, February 3), I have doubts about it.
And then New Hampshire’s own website seems to indicate its deadline is tomorrow, November 15—and it isn’t on the Ballotpedia list.
Likewise, this New York Times article lists November 26 for California—which I have also seen elsewhere—but it’s also not on Ballotpedia’s list. Going to California’s own page suggests that November 26 is the deadline for “Proof of Generally Advocated for or Recognized Candidate,” but it’s unclear to me what that means. Can a candidate can be included on the ballot during the “Nomination Paper Period for Presidential Candidates not Selected by the Secretary of State,” which ends December 13, if they have not submitted said “Proof” by November 26?
Does anyone know where the actual, official, current information can be found? Ideally without having to go to each individual state’s websites (and hope I’m not stumbling upon some outdated page, or misunderstanding what those pages are saying)?