It's a complicated issue, so as an attorney I'll try to unpack it in a digestible way. I hope you'll share this with others.
So you see how complicated this all is.
(1) This is all so f*cking confusing that there's a *damn good reason* no legal pundit on TV is willing to touch the "Can Trump invoke the Fifth in this situation?" question.
(2) Trump is unlikely *ever* to testify.
Not just of Obstruction, but of Conspiracy relating to computer crimes, election law, money laundering and possibly far worse.
But if Mueller needs any final confirmation—in his heart—that Trump committed Obstruction, that invocation will do it.