Michael Tomasky, writing in the New York Review of Books:

Arguably every single tweet the president writes about the investigation, attacking Mueller’s “13 Angry Democrats” and denouncing it as an invariably upper-cased Witch Hunt, is an attempt to obstruct justice; if you don’t think so, get yourself placed under federal investigation and try mimicking Trump’s Twitter habits and see what happens to you.

All of this doesn’t begin to detail what Mueller and his team have learned from interviews about what took place in private. It’s a reasonable bet, then, that Mueller will find that Trump and others around him—former press aide Hope Hicks, possibly his son Donald Jr., maybe Jared Kushner, other campaign associates and hangers-on—have lied or tried to quash or in some way compromise the investigation.

If that happens, what comes next? Three days before Trump’s inauguration, the neoconservative Bush administration official Eliot A. Cohen wrote that “this will be a slogging match until the end.” He felt confident, however, that “the institutions will contain him and the laws will restrain him if enough people care about both, and do not yield to fear of him and whatever leverage he tries to exert from his mighty office.”

Of those forty-five words of Cohen’s, the most important is “if.”

Spot on. And, given the current crop of Republicans in both the House and the Senate, I think we know the answer.