The term "wartime president" didn't really come up until WWII, when FDR rallied a nation, set about fighting an actual war, with an actual enemy, to produce ships, planes, equipment, and more. He acted in a way that would support the growing war effort.
So there is no clear definition for the term. However, it's been applied at times to presidents who rallied a nation to fight a common enemy.
Each had the courage to take personal responsibility for their actions – and, equally courageous, for their inaction. The courage to admit error and learn from it.
As I noted earlier the term was coined under FDR, and somewhat became a thing because of what Winston Churchill did in England in 1940. In short, he saw Germany as an aggressor and boosted production of aircraft, taking a risk in rallying a nation. He said of this: "To each there comes in their lifetime a special moment when they are figuratively tapped on the shoulder and offered the chance to do a very special thing, unique to them and fitted to their talents. What a tragedy if that moment finds them unprepared or unqualified for that which could have been their finest hour."
Roosevelt a short time later, likewise rallied our nation to achieve greater things. And this is how he became the war time president. He harnessed the power and prestige of the federal government to mobilize the national effort.
First he saw the threat.
First he saw the threat.
And the second thing he did was financial. He managed to get appropriations to support the effort.
After that, he directed companies to produce ships, equipment, aircraft, and equipment.
And he did this *before* Germany invaded France, because he saw the threat mounting and acted decisively to counter it.
FDR was well aware of the risks. And he proceeded in spite of them. He didn't shrink, rather he got bolder. There were many who preferred that America ignore foreign conflicts. Amusingly one was called "the America First Committee" which sounds like something trump might have made a slogan.
Roosevelt said of them: "Frankly and definitely there is danger ahead—danger against which we must prepare. But we well know that we cannot escape danger, or the fear of it, by crawling into bed and pulling the covers over our heads."
And I should note that the other president who you could say presided over a war in that sense was Lincoln.
It might very well be the most apt parallel to today. The nation was divided over something that seems almost silly. And as it happened, the Union sustained a long string of battlefield defeats in the first years of the Civil War. But Lincoln did not blame these losses on the generals, the Union governors or anyone else. Instead he made the hard and unpopular decision to pursue the war – fully expecting that it would cost him his reelection.
Because it was in the best interests of ultimately uniting a nation.
So trump thinks this will help him with re-election, even though he has done exactly the opposite of what FDR or Lincoln did.
Trump punted on responsibility for preparation and said early on that "We pretty much shut it down coming in from China" and later doubled down saying "It's going to disappear. One day—it's like a miracle—it will disappear."
And then when it did spread here, he had the audacity to say, "I don't take responsibility at all."
And as for the decisions Roosevelt made in gearing up production, trump didn’t and then said this "We're a backup. We're not an ordering clerk. We're a backup." Trump essentially told states to procure materials on their own, saying the federal government is "not supposed to be out there buying vast amounts of items and then shipping. You know, we're not a shipping clerk."
If you look at what it takes to be successful, it's four things. Let’s look at those and see how trump did. (1) accountability. He gave us the middle finger. (2) financial. He never asked for funds to do anything. (3) working at defeating an enemy. There isn't one. If you say it's the virus then what is he doing to try and defeat it? And (4) Gearing up production for a greater good. He didn't rally us to do anything. In fact if there’s an opposite, he’s doing that.
So for comparison, let's look through history and see presidents who were in office during a war, let's see how they did in their re-election bids.
War of 1812 - James Madison. Won re-election, though the war wasn't a huge factor.
Civil war - Lincoln, won re-election but died in office. Andrew johnson served afterward, as the war ended, and was not re-elected. .
World war 1 - Woodrow Wilson. Won re-election as the war was ongoing.
The depression - not so much a war but it was another big moment. Herbert Hoover was president. Lost his bid for re-election
WWII - FDR, won re-election several times. But he also took over and led us in rebounding from the depression; he may have been our nations greatest leader.
Korea - Harry Truman Lost his bid for re-election
Vietnam - this one swallowed up many presidents including Eisenhower (not re-elected), Kennedy (died in office), Johnson (He was re-elected but the kennedy assassination was a driving factor more than the war), and to a point Nixon (left office). Ford took over and led us to the end of the war but also wasn’t re-elected
Cold War - this was fairly complicated and spanned for many years. You could argue that that Reagan won re-election based at least in part because of his efforts in the Cold War.
Iraq - elder bush was not re-elected.
Iraq - elder bush was not re-elected.
9/11 - again not so much a war, but W won re-election
So as you can see, the bump that trump perceives as a benefit for his re-election isn't necessarily that. When the nation is in peril, the eyes turn to the leader. If they are good at their job and lead us through it, they get to remain in office. And if not, then the person behind the deli counter is saying "next!"