You’re changing the subject. You argued that Twitter might be liable for libel. In order for that to be true, then the speech in question must be libelous.

So, even ignoring 230, is mislabeling a satirical argument as false libelous? It is without a single doubt not libelous.

First of all, defamation (the larger category that includes libel) usually requires a statement of fact, whereas something being satire vs. just plain wrong is a matter of opinion. It is very hard to sue over matters of opinion, by design. This is why saying “the president is stupid” or “the president is racist” aren’t libelous; those statements are opinions and not objective statements of fact.

Second, defamation either needs some form of harm, or it needs to be in a narrow category of statements that are defamation “per se”. The latter category is very narrow and not relevant here, so we can focus on the former. What, pray tell, harm did the president suffer?

Finally, the president is a public figure, and the bar for defamation against a public figure is very very high. The standard is “actual malice”, which requires that Twitter knew that they were lying and did it anyways. If Twitter genuinely believed that the video was not satire, even if you think that’s dumb, then they have a rock solid defense against defamation.

So no, this was not libel. Nowhere close.