You accused me in your first reponse to me on this subthread of having a mind impossible to change. What I'm looking for is correlation; that would make me reconsider my position. While correlation is not causation, a causal explanation ("mail-in ballots make it easier to commit undetected fraud") without a correlation it predicts is highly suspect. Find correlation between the states that have had mail-in voting for longer periods of time, and for more people, and identified instances of voter fraud. Confirm there are more instances in those states than in states that have more curtailed access to mail-in voting. Tricky to get the numbers right (probably have to do a state-by-state search of laws to find when they enacted no-excuse absentee voting), but here's the list of states that allow it (https://www.ncsl.org/research/elections-and-campaigns/vopp-t...) and here's a collection of voter fraud incidents identified (https://www.heritage.org/voterfraud-print/search?name=&state...).

I haven't spread-sheeted this, but at a first glance I'm not seeing a correlation between no-excuse-needed mail-in and fraud. Alaska allows no-excuse-needed and has 0 instances recorded. Texas does not allow it and has ~25 recorded.

The President's administration itself commissioned a study on voter fraud and did not find widespread fraud activity (https://apnews.com/f5f6a73b2af546ee97816bb35e82c18d/Report:-...).

To pop this entire discussion up a meta-level to the original topic: clearly this is, at least, a controversial issue. I think given the combination of the controversy, the President's one-sided take on it, and the authority from which he speaks granted him by his office, Twitter was at least justified in fact-checking him. This is a controversial topic, and he speaks as though it is not from a position of authority encouraging people to believe him without questioning the details. I appreciate you question, even if your conclusions disagree from mine; in contrast, the way Trump uses his Twitter feed to push one side of a topic juries are still out on is irresponsible as a President, and while Twitter taking "the medium is the message" somewhat literally in fact-checking him makes me slightly uncomfortable in terms of what larger rules they might employ, I'm glad somebody from an equivalent position of authority to his voice on their service is doing so.

... and we should probably all find the response of the most powerful civil servant in the United States being to threaten to close that institution in response, unconscionable.