[BroJoeK]

DiogenesLamp: "I have actually ran across quoted bits of this discussion, and if memory serves me right, I believe what Justice Chase said was "You will lose everything in the courtroom that you gained on the battlefield.""

Several things need to be pointed out here:

1. Chase was a fickle politician, a RINO, similar to some today, he served as Lincoln's Secretary of Treasury during the Civil War, then switched parties and ran for the Democrat nomination for president after the war.

2. Chase's words, if accurate, are obviously true considering that Davis would have been tried for treason in Richmond, VA!!
   It would be like today, John Durham trying to get convictions for anti-Trump conspirators in Washington, DC!
   Not going to happen.
   Had such a trial been held in, for example, Boston, then Davis's conviction would be a near certainty.

3. Chase was convinced Davis's best defense would be that he forfeited U.S. citizenship upon secession, and therefore could not have committed treason.

4. In 1868, Chase himself dismissed treason charges against Jefferson Davis based on the argument that the new 14th Amendment prevented further punishment of former Confederates.

So, arguments over alleged Confederates' treason are strictly theoretical, hinge on whether you consider Confederates to have legally left the Union, which no Congress or Supreme Court ruling ever did, but which Democrat Chase himself was willing to contemplate.
However, that was not the argument which Chief Justice Chase used to dismiss treason charges against Jefferson Davis.
Rather, Chase said, in effect, "Davis has already been punished enough, no double jeopardy for Confederates."

[Locomotive Breath]

Davis would have been tried for treason in Richmond, VA!!

Ummm... not sure about that. Please provide support for that statement. Nothing prevented the victors from trying him in DC. Or Boston for that matter. If secession makes you no longer a citizen and are therefore not treasonous then why is the secession itself not legal? Lincoln's suspension of habeous corpus and arrest of the Maryland legislators are well known. Engineering a move to Boston or assuring that in Richmond only pro-Union citizens were on the jury would have been easy enough to engineer. Simply say that anyone who fought for the South or was a Southern sympathizer is no longer a citizen would have been enough to exclude from the jury. I'm sure that even in Richmond they would have found 12 pro-Union jurors.

That's always been the Union dilemma and double talk. If you can't secede then the South never left the Union and everyone in the South retained their Constitutional rights as citizens, but were also liable for treason under Federal law including trial by jury. If you can secede then everyone in the South was temporarily part of another country, no longer citizens of the U.S., and not subject to prosecution under Federal law.