They're deserting what appears to be a sinking ship. And we're starting to see the outline of an excuse from those who have jumped overboard. The rough outline goes like this:
"I did what I could to save the country from Trump and I could only do that from the inside."
They weren't mitigating the damage. At worst they were enabling and covering it up. At best, they were merely stretching out the amount of time that Trump got away with it in order to advance their own (usually ethically dubious) agendas.
In other words, there were never any "guardrails around the Trump presidency." There were only grifters.
Sure, the quip Mattis's speechwriter wrote about bone spurs is amusing. But it doesn't let him off the hook. He's as morally culpable as Barr, Miller, Mnuchin, Mulvaney, Pence, and the rest of the Whole Sick Crew:
Thomas M. Nichols, a professor at the U.S. Naval War College in Rhode Island, said he did not think the speech was an occasion for laughter.
“I don’t think anyone should be chuckling at Mattis’s brush off of Trump’s insult,” he wrote on Twitter. “It’s his facile way of dodging the reality that he knows a lot about what happened in this White House, including what are now obviously impeachable acts directly related to his time as SECDEF.”
That is exactly right. And by the way, being a serially bad judge of character — the only conceivable (and feeble) excuse for Mattis's agreeing to serve on the Board of Theranos and in Trump's cabinet — does not absolve Mattis his responsibility to come forward about any wrongdoing he witnessed or possibly partook in.