Should Mail-In ballots be banned in the 2020 US Elections?

Foreign countries will sway US elections with counterfeit ballots

Question: Should Mail-In ballots be banned in the 2020 US Elections?
Position1 of 2›: Yes, mail-in ballots should be banned in the 2020 US Elections.
Argument‹4 of 6›: Foreign countries will sway US elections with counterfeit ballots

Both Attorney General William Barr and President Trump claim foreign adversaries will take advantage of an increase in mail-in voting by printing counterfeit ballots to commit fraud on a massive scale and skew the election.

The argument

Critics of vote-by-mail worry that it will lead to foreign countries swaying US elections with counterfeit ballots. Attorney General William Barr said during a House Judiciary Committee that mail-in voting could lead to foreign countries swaying US elections with counterfeit ballots. Though he admitted that there was no evidence, he claimed the possibility exists. This was then echoed by Donald Trump’s Twitter where he claimed foreign powers would "print millions of ballots" and "it will be the scandal of our times!" The US has never had an election with the scale of mail-in voting which is expected in 2020, and therefore this is an unknown which worries many people suspicious of mail-in voting.

Premises

[P1]Critics, including Attorney General William Barr, warn that large-scale mail-in voting could let foreign countries sway US elections with counterfeit ballots—a possibility Barr conceded lacked evidence but considered real. [P2] Because the US has never run an election with the scale of mail-in voting expected in 2020, this unprecedented unknown worries those suspicious of the practice. [C] Therefore, on this view, mail-in ballots should be banned in the 2020 US elections.

Counter-arguments

Attorney General Barr himself admitted he has no evidence to back the claim that foreign powers will take advantage of an increase in mail-in voting to sway the election.

Rejecting the premises

[Rejecting P1] The premise concedes the central point — the claim was made without evidence — and a stated possibility is not a finding; counterfeit ballots would also have to defeat the envelope signatures, ballot tracking and voter-roll matching against which returned ballots are checked. [Rejecting P2] Novelty of scale is a reason to prepare rather than to prohibit: several states had already been running elections entirely by post for years, which is the evidence base the premise treats as absent — and a ban would disenfranchise voters on the strength of a risk no one has shown to exist.