You say I'm wrong, and then seek to explain how by citing court deliberations. I have looked at the makeup of the Majority in that decision. Northern Republicans and one Louisiana Democrat (Creole Country) against two Democrats.
The fact that the court intentionally ignored the Debates on the 14th amendment, and the Civil rights act of 1866, as well as completely ignoring the war of 1812, leads me to believe their decision was simply the result of wanting to create a political rebuke of Democrats, and may have had nothing to do with what the law actually was. The sought out the law they wanted to justify their decision, and weren't interested in looking at anything that would not.
The Era after the civil war was full of examples of Republicans trying to shove Democrat's faces into Racial rebukes. It was the era of "the bloody shirt" and the animosity appears to have extended to the courts.
“The fact that the court intentionally ignored the Debates on the 14th amendment, and the Civil rights act of 1866...”
This is normal for a court. They are less concerned about what was proposed, and more concerned with what was passed. Courts resort to ‘legislative intent’ when they have no other options, because it is very hard to figure out years later why a majority voted for some wording. The debate is often more about scoring political points with constituents than it is with what passed, or why.
The WKA ruling discusses the Founder’s original intent for NBC by reviewing what it meant at the time it was written, and passed without debate. When they go on to the 14th Amendment, they did what every court does, and looked at the wording that passed.