"While protesters listened to music, planned their actions or slept, the authorities quickly moved in 10,000 Federal troops to various locations in the D.C. area, including 4,000 paratroopers from the U.S. 82nd Airborne Division. At one point, so many soldiers and marines were being moved into the area from bases along the East Coast, that troop transports were landing at the rate of one every three minutes at Andrews Air Force Base in suburban Maryland, about 15 miles from the White House. These troops were to back up the 5,100 D.C. Metroplitan Police and 2,000 D.C. National Guard troops that were already on the streets."
Big difference. The "protesters" were already proven to be a lot of violent slime. I lived through the sixties and watched the Chicago riots. The city had reason to fear.