Any flexing of military muscle on domestic soil, or, indeed, any presenting of the military on a political par with civilian life, has always been a big no-no in democratic society. The president’s July 4 “Salute” speech at the Lincoln Memorial with tanks, troops and military brass in attendance is an example of edging toward autocracy and a military state.

For one thing, military movement into a nation’s capitol is one way to intimidate or usurp the supreme power in a democracy, in our case the Congress.

Americans worried when Andrew Jackson, as general of the Army in Florida, asserted the military’s political independence from civilian leaders, got in trouble for it, and then ran for president. Americans gasped when Abraham Lincoln quelled anti-war draft riots in New York City with an army. When Dwight D. Eisenhower ran for president after leading troops in World War II, the nation discussed the obvious danger.

One retired American general commented on Trump’s plans for the day with “Leave tanks for Red Square.” College-educated Americans who have studied some classical history will think of Caesar crossing the Rubicon — the day the Roman “president” became an emperor.

We’re not there yet, but we’re getting closer.

Robert Kimball Shinkoskey, Woods Cross