evidence: Does America adapt by crisis or consensus? Do we spontaneously change because we see we must, or must we be coerced by events that leave us no choice? [...] It is also true that, on paper at least, some problems are amenable to compromise. Take immigration. The bargain that could be struck has long been clear: Most of today’s roughly 11 million "illegal" immigrants would be granted legal status; in return, border security (yes, including the dreaded "wall") would be strengthened, and legal immigration would be overhauled to emphasize skills, not family ties. [...] President Trump is the logical conclusion of these tendencies. With his tweets, he has devalued political discourse and aggressively divided, rather than unified, voters.