Trump has run two argument claims today based entirely on sign arguments (the appearance or presence of thing X is a natural indicator of other thing/event Y).

His sign arguments are laughably weak, let me explain.

Here: winning OH & FL is a sign of winning the election.

1: not true, Kennedy won in 1960, but lost OH & FL. h/t @KevinMKruse

2: there's no "natural" relationship between winning those two states & winning the election.

3: there's no causal link b/n winning OH & FL & winning.

Here: betting market odds are a sign of winning the election.

1: this is not true. Betting markets predicted Biden would win. Trump doesn't specify which "bookie" he means, so it's hard to judge what he means (that's on purpose so you can't fact-check him).

2: as above, there is no natural relationship between betting markets and winning the election.

3: as above, there is no causal relationship between betting markets and winning the election. Betting markets don't vote for president, people do.

A good sign argument explains the natural relationships between things that allows you to read the sign as evidence of something else.

A fever is a sign that you have an infection. Loss of smell is a sign that you have Covid, etc.