Sally Kohn is a CNN political commentator and the author of the forthcoming book "The Opposite of Hate" (April 10, 2018). Follow her on Twitter: @sallykohn. The opinions expressed in this commentary are hers.

(CNN) One FBI lawyer texted an FBI agent with an apparent joke about a "secret society" and Republicans went crazy. By which I mean, crazier than usual. The problem is that in doing so they have implicitly enforced a set of rules some Republicans themselves frequently, flagrantly violate.

It started with the discovery last summer that FBI agent Peter Strzok had exchanged anti-Donald Trump text messages with a colleague, Lisa Page. Special Counsel Robert Mueller removed Strzok from the Russia investigation team (Page had already left the investigation before the discovery of the texts).

But the agent's prompt dismissal then -- and the Justice Department's announcement Thursday that it had recovered a trove of texts between the two that had gone missing -- hasn't stopped Republicans from trying to use this cooked-up controversy as an excuse to scuttle the entire Mueller probe.

Republicans have been trying to suggest that Strzok is just the tip of the iceberg and, fundamentally, that he couldn't possibly have been impartial and fact-based in the Russia investigation.

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Hence conservatives latched onto the "secret society" text, a text that existed for them completely out of context, didn't mention Trump or Republicans at all, was, incidentally, written by Page, not Strzok, and -- as most of us who have ever used our thumbs to tap out a message can probably similarly attest -- was probably a joke.

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