Trump is going all in on divisive culture wars. That might not work this time.

Presidents tend to offer messages of national unity and optimism on Independence Day. But this weekend, President Donald Trump marked the occasion with a pair of speeches in which he described himself as presiding over a cultural civil war against an insurgent left — and promised to vanquish those on the other side of that war through aggressive use of law enforcement.

In a speech at Mount Rushmore on Friday, Trump warned of a “far-left fascism” that is part of a “merciless campaign to wipe out our history, defame our heroes, erase our values, and indoctrinate our children.” As the …