For many, if not most, Americans, the only pleasure to be had from Donald Trump’s presidency is to imagine his premature eviction from the White House. Impeachment, the 25th Amendment, pick your poison. My own scenario places Trump on Richard Nixon’s Watergate resignation timetable, fleeing next August to Mar-a-Lago as federal bloodhounds close in on him, his son, or his son-in-law (or all three) and his party’s Vichy regime on the Hill at last mutinies in the face of what could well be an apocalyptic Election Day in 2018. In private, Steve Bannon reportedly gave Trump only a 30 percent chance of finishing his term, even before Robert Mueller dropped his first indictments. (Bannon has denied saying this.) And there are other fresh signs of an advancing Trump expiration date besides, from the resounding Democratic wins in Virginia and New Jersey on November 7 to the epic failure of the Republican Congress to accomplish anything. But don’t celebrate just yet. Once Trump exits — whenever and however he goes — then what? It’s a continuing liberal blind spot to underestimate the resilience of Trumpism, which, if history is any guide, will easily survive both the crack-up of the GOP and…