The greatest threat that free speech currently faces in this country is that the president doesn’t believe in it. Donald Trump treats criticism of himself, his administration, and his policies as fundamentally illegitimate, and he is eager to use government power to curtail it. When Trump’s allies downplay or spin the anti-speech activity flowing downstream from his whims, they engage in willful ignorance or deliberate deception. Trump responded to Jimmy Kimmel’s Tuesday night return to ABC’...