When they break the law or commit sedition against the United States? You bet!
Why were none of the Confederate leaders, including Jefferson Davis tried for treason after Lee’s surrender?
Mostly due to Lincoln's kind benevolence when he issued instructions to "let them up easy". Lincoln didn't want the war that he was given, had no desire to hold a grudge, and wanted the nation to heal. After his cowardly murder there were many who wanted revenge against the confeds but cooler heads prevailed.
The Taney Supreme Court might not have allowed a conviction for treason to stand but Taney died in 1864 and was succeeded by Chase. Your Chase quote is interesting but not particularly persuasive since this is the same Salmon P. Chase that rendered the ruling against the legality of secession in the Texas v. White case.
In any event, decisions to continue prosecution for treason were abandoned because in the view of Chief Justice Chase, (who would have presided over such a trial) the ratification of the 14th Amendment with the punitive measures contained in Clause 3 meant that Davis had been punished once for his actions in leading the rebellion. Trial, conviction, and additional punishment would have violated his 5th Amendment protections against double jeopardy.
Thanks for that clear & brief summary.
I've never understood that logic before.
Chase believed the 14th amendment already punished former-Confederates and therefore further punishments would amount to double jeopardy.
Hmmmmm...