While the annual Army-Navy Game might be one of the U.S. military's oldest ongoing traditions, it's an event that has not always included the Commander-In-Chief. Only ten U.S. Presidents have attended the game at one time or another, but if the nation's chief executive decides to come, there are traditions for that office to follow when Army plays Navy.
President Trump has attended the game for nearly every year he's been in office, including attending as President-Elect. While there is no precedent that says he has to attend the game, the very fact that he goes every year could set a new precedent, all the same, creating a tradition for future Commanders-In-Chief to follow throughout their administrations. Woodrow Wilson did something similar when he attended the game, creating a tradition that carries on to this day when the POTUS is in the house.
Although Wilson wasn't the first American President to attend (that was, of course, the most athletic and all-around competitive President, Theodore Roosevelt), Wilson started the tradition of switching sides during the middle of the game, walking across the field at halftime in order to show no favoritism toward Army or Navy as the game continued. Presidents in attendance from Calvin Coolidge through President Trump have walked across the field ever since.
For many years following the Coolidge Administration, the President did not attend the game. Watching a raucous football game in the middle of the Great Depression and the Second World War might have sent a bad message. But once the economy turned around and the Axis was defeated, President Harry Truman returned to the game for much of his administration. But it wasn't until President John F. Kennedy helped throw out the pregame coin toss that another Presidential tradition was born. His immediate successors did not attend, but Navy veteran Gerald Ford sure did. The next President to attend would be Bill Clinton, however. And ever since, Presidents have attended at least one Army-Navy Game during their administration.
One presidential event that didn't catch on was when George W. Bush gave the Naval Academy Midshipmen a pregame speech and a pep talk to the Army Black Knights before the Army-Navy Game as American troops were fighting to avenge the attacks of Sept. 11, 2001 – a special consideration for a wartime President.