Trump has been headed down this path from Day One. Look back at all the things that have happened since January: The firing of Comey, the attacks on legitimate media as "the enemy of the American people" and the non-stop refrains about "Fake News," the beyond-dubious pardon of Sheriff Joe Arpaio, the constant lies that you can disprove either with the naked eye (inauguration crowd size) or a 30-second fact check (that Trump doesn't know his sexual-misconduct accusers), and the growing demands on Republicans on Capitol Hill for unfettered loyalty or to see your political career end (like Sen. Jeff Flake) — all of these things have been trial runs to see what the president can get away with. In other words, it's all been a test to see if Trump could pull that "Saturday Night Massacre" and, unlike Nixon, survive. Since he's gotten away with so much so far, why wouldn't Trump get Mueller fired?