Two new pieces went up today. One is on The Week and offers a closer look at what I think Trump is most worried about Mueller's investigation poking around in. Hint: It's something members of Congress have been indicted for in the recent past.
The second is on Rolling Stone and looks at the design of the presidency and the need for presidents to be knowledgeable. Surprisingly (or perhaps not, depending on how much attention you've paid to the Constitution and your history classes) the Executive Branch is designed so that a pretty thoroughly mediocre person can do the job without the system breaking down. However, we've tested and now surpassed the lower limits of presidential competence required to do the job. Without it, the whole thing is going haywire.