Someone beat me to the obvious answer that a final showdown would see Andrew Jackson, Abraham Lincoln, and Teddy Roosevelt doing a dagger-wielding version of a Mexican standoff, so I took it too far and walked through how I thought every president would turn out.
Now, clearly, dude is wrong about some things. For instance, there's no way Teddy Roosevelt makes it to the final three. But he's got some great reasoning, too. About Reagan he says, "Twenty years after the battle people will rewrite the fight to make him a lion among bobcats, but that’s mostly driven by nostalgia."
Anyway, here are the rules:
* Every president is in the best physical and mental condition they were ever in throughout the course of their presidency. Fatal maladies have been cured, but any lifelong conditions or chronic illnesses (e.g. FDR’s polio) remain.
* The presidents are fighting in an ovular arena 287 feet long and 180 feet wide (the dimensions of the Roman Colosseum). The floor is concrete. Assume that weather is not a factor.
* Each president has been given one standard-issue Gerber LHR Combat Knife , the knife presented to each graduate of the United States Army Special Forces Qualification Course. Assume the presidents have no training outside any combat experiences they may have had in their own lives.
* There is no penalty for avoiding combat for an extended period of time. Hiding and/or playing dead could be valid strategies, but there can be only one winner. The melee will go on as long as it needs to.
* FDR has been outfitted with a Bound Plus H-Frame Power Wheelchair, and can travel at a maximum speed of around 11.5 MPH. The wheelchair has been customized so that he is holding his knife with his dominant hand. This is to compensate for his almost certain and immediate defeat in the face of an overwhelming disadvantage.
* Each president will be deposited in the arena regardless of their own will to fight, however, personal ethics, leadership ability, tactical expertise etc., should all be taken into account. Alliances are allowed.
Now, I think there's a good argument to be made for the Bushes going really far. They've got a natural alliance. I think GWB would fight like hell for his dad and GHWB was a CIA man! You can't overlook the benefit of that. I think GHWB ends up taking GWB out, though, when it comes down to it.
Obama either goes down early due to the racist conniption fit some presidents would throw or he gets to the middle of the fight by taking advantage of the "Really?" pause to cut some folks down. He's got an element of surprise no other president has.
But I've become convinced that LBJ is among the final three. He's tall, has reach, and has some heft to throw behind a swing. And, of course, Lincoln is among the finalists. He's brilliant, well-known for his strength, and a scrapper from back in the day.
But I just keep thinking of Jackson in his big coat dueling Dickinson. Remember how he turned inside the coat to keep Dickinson from hitting him square?
I imagine Jackson would somehow know to arrive at the knife fight in a kevlar lined parka that had eight inches of stuffing. The crowd would be all "I didn't realize Andrew Jackson was so portly" and then he'd just dominate because no one could land a truly damaging blow.
Jackson clearly wins.