I saw a post on Facebook the other day proposing that there be a requirement for the Presidency of prior military service. And my first thought was, 'Well, that's dumb.' There is absolutely nothing wrong with military service. It's an honorable desire to serve one's country, and to be willing to die for it and its citizens. Military service can be valuable experience for someone in a leadership, both in terms of learning leadership and learning how to serve others.
But a requirement?
18 of our 44 presidents to date did not serve in the US Military (some of those did serve in local militias, and 1 - George W. Bush - was in the National Guard). Interestingly, at least to me if no one else, every president from Truman to Reagan was involved in a World War. So there is a precedent set by this slim majority of the President being a military man.
However, if you look at the men themselves, our country would be significantly worse off, to the extent of possibly not even existing, had this been a Constitutional requirement.
Of the Founding Fathers who became presidents, only 2 served in the military (Washington and Monroe). So Thomas Jefferson, author of the Declaration of Independence and significant influencer on the development of Constitutional law and legislation, as well as the force behind the Louisiana Purchase, is excluded. John Adams, the "father of the Constitution" and another heavy influence on the formation of American governance, is likewise cut out of his place in history, as are James Madison and John Quincy Adams.
Abraham Lincoln, widely regarded as our greatest president, save only Washington, was not a military man. He was part of a local militia in his youth, but that's hardly the same as being in the Army. Would the US even exist without Lincoln's influence? Obviously it's impossible to know for sure, but the magic 8 ball would probably give an "outlook not so good."
In similar vein, Franklin D. Roosevelt couldn't serve in the military due to his medical condition. Did that lessen his effectiveness and importance in ending the Great Depression and seeing the US through (most of) World War 2?
The whole premise is silly.
Now, if you want to make a more practical argument about valid Presidential requirements, how about they must be a southerner? Between presidents born in the south and those raised in the south, more than half have been southerners. Or, to get even more specific, they should be from Virginia (Washington, Jefferson, Madison, Monroe, Harrison, Tyler, Taylor, and Wilson) or Ohio (Grant, Hayes, Garfield, Harrison, McKinley, Taft, and Harding).
Facebook posts don't make for good policy-making, I guess is my point.