Would President Trump Impose Martial Law?

My wise friend asked this question over breakfast this morning at LaPeep. I almost choked on my veggie omelet. Remarkably, that seems possible, especially if the U.S. had a Boston Marathon or San Barnardino-type attack on his watch. Would Trump round up all Muslims and put them in concentration camps? Or would he use this power to round up 11 million unlawful aliens?

So, here is the short answer: Congress enacted a statute in 1878, the Posse Comitatus Act, which forbids military involvement in domestic law enforcement without congressional approval. It came about after more than a decade of federal occupation of former Confederate states (recall Reconstruction). A bitterly disputed presidential election, somewhat similar to Bush-Gore in 2000, was the impetus for the law. It’s been invoked only once, when President Eisenhower used federal troops to enforce a school desegregation ruling by the U.S. Supreme Court. There, now, are you relieved? I didn’t think so. (Note: Both chambers of Congress are under Republican control, so....)