Politics then was like politics now, with Democrats in minority and majority Republicans split between "moderates" (today's "RINOs") and "radicals" -- "radicals" then meaning abolitionists and unconditional surrender-ists.
Democrats then, like Dems now, were much the party of compromise & surrender, but they did nearly all join the war effort, an outstanding example being New York's famous "fighting 69th" & Irish Brigade, which suffered more casualties than any except Wisconsin's (plus Indiana & Michigan) Iron Brigade.
soakncinder: "The South didn't have to invent anything.
There are newspaper accounts from the period, political speeches etc. that declare what people thought, many of whom thought Lincoln was abusing his power."
Once the Confederacy provoked, started & formally declared war on the United States, then the US Constitution's definition of "treason" came into play: levying war against the United States or providing aid & comfort to our enemies.
Naturally, Dems as the party of compromise & surrender to our enemies, were taken aback at the Constitution's power to attack treason, but Lincoln did what he must to, as his oath of office required: "preserve, protect and defend" the Constitution.
soakncinder: "And the Old Slave Power was the United States of America, and before that it was England, so it just depends on how far back you want to go to prosecute our forebears."
No, no, FRiend, you seriously misunderstand our history.
That term "Slave Power" was a political epithet of the time, and it referred, precisely, to those from slave-states who were elected to federal office based on the Constitution's 3/5 of slaves rule.
Indeed, the first US President elected by slave-power, and therefore called the "Negro President" by his opponents, was none other than Thomas Jefferson, in 1801.
Generically, "slave-power" referred to all Southern politicians whose main focus was preserving and advancing the cause of slavery.
You might be interested to learn several other political terms of that time:
Republican Wide-Awakes, circa 1860:
BS, one of them ran as vice president with McClellan in '64. Copperheads were not hunted down at all. they were a viable political force in the North.