But on one notable issue, they were in complete agreement: they both think people on the federal government's "no fly list" should be categorically denied their right to buy guns under the Second Amendment. Both candidates have repeatedly said so for months. Trump's stance on this issue should be deeply troubling to those who care about gun rights – and also to people concerned about constitutional rights generally, even if they don't care much about this one.

As both the ACLU and conservative commentators point out, the no fly list is notoriously inaccurate. It is also provides little or no due process protections. The process is secret, people are not told the reasons why they were placed on the list, and they are not given any advance opportunity to challenge the designation. And, once on the list, even a completely innocent person might find it difficult and time-consuming to get off it.