I strongly recommend you read Josh Kovesnky’s account of why the US government’s vaunted intelligence capabilities were caught utterly flatfooted by the events of January 6th despite that fact that one needed no greater intelligence asset than a Twitter account or at most one on Parler to know what could be coming.
A key cause of the failure is that no one wanted to raise an alarm about a security threat from the President’s own supporters. Indeed, no one really wanted to be caught investigating it.
This is both a shocking abdication of responsibility and entirely unsurprising given what’s happened to basically anyone in the federal security bureaucracy who’s gotten crosswise with the President. But we can’t understand this development without understanding or simply remembering that this is our fourth or fifth round of this cycle: the institutional Republican party rushing forward to claim that any effort to combat far right terrorism or organized political violence amounts to a crackdown on conservatives or bias against the GOP.