insisted that the 14th Amendment essentially extended the full limits on Federal power as per the BoR to also be authorative over the several States. Legally, I can't see how this is even feasible.
Outside its area of enumerated jurisdiction, the federal government doesn't even HAVE any 'civil authority' because it's not a civil entity, it's an administrative one.
And you're right, it doesn't have the authority to extend itself beyond that, no matter which of the 3 branches it is.
Sad to say it, the Butchers of New Orleans found a Chief Justice and two Associate Justices who were willing to agree with them even way back then.
I don't know much (yet) about Swayne, Field and Bradley––the three radicals in question.
Unless I'm mistaken, Bradley was responsible for the majority opinion in the Civil Rights Acts Cases decision that struck down the Civil Rights Act of 1875 which makes me wonder if he wasn't really a partisan for federal supremacy rather than a 'bring about the end of slavery' flavor or Republican.