My take, from reading on the American Civil War, is that Jefferson Davis was the Donald Rumsfeld of the Confederacy. He made bizarre personnel decisions based upon personality rather than upon whether people were doing the right thing. He utterly ignored significant logistical problems such as the state of the Confederate railroads, diverting all resources needed to keep the Confederate logistical and communications infrastructure going into building ironclads that made no (zero) difference in the outcome of the war. He relieved generals who were doing a good job with limited resources, such as Joe Johnson who was trying to keep Sherman from marching anywhere Sherman wanted, and micromanaged things that did not need micromanaging such as the operations of the Army of Virginia. He appointed people because they were yes-men rather than because they were the best man for the job, he was arrogant, he was a tyrant towards his subordinates, in short, it is unclear how this man could have ever been considered qualified to be President of the Confederate States of America. Except, well, he had been Secretary of War under President Franklin Pierce so everybody apparently assumed he would know how to run a war better than some random joe off the street. But he didn't.
My take: Jefferson Davis shows that a military background is no guarantee that a man can lead. The Confederacy's logistical problems were enormous. At the beginning of the war, for example, the Confederacy had only one ironworks capable of building locomotives (in Richmand VA). Yet Davis pursued a quick and glorious victory while ignoring the logistical problems entirely, diverting that ironworks to building ironclads rather than maintaining the Confederate railroads, eventually leading to the collapse of the Confederate rail network, and, therefore, the collapse of the Confederate armies as they literally starved while thousands of tons of food rotted at railheads for lack of trains to move them to where the armies needed them. Tactics win battles. Logistics win wars. By ignoring logistics, by putting the railroads way down on the priority list to where he didn't even give his "railroad czar" a staff or any power to nationalize recalcitrant railroads the way Lincoln did, President Davis insured the collapse of the Confederacy as its armies literally starved to death.
What is bizarre is the cult that Southerners built around Jefferson Davis after the war. He had clearly been incompetent and inept as President of the Confederacy. Yet every single Southern state has counties named after him, monuments all over the place to him, and so forth. It is to laugh, how the losers build a cult around the person who led them to disaster.
-- Badtux the Puzzling Penguin