>Easily half the states demonstrated that they could not be trusted to run their own affairs and protect the rights of the citizens enshrined in the Constitution.

So instead we have a more centralized federal government that cannot be trusted to protect the rights of the citizens enshrined in the Constitution ( that same post civil war government interned the Japanese, allows police to search any vehicle with the "signal" of a dog, and instead of enslaving blacks just disproportionately tosses them to wither away in prison instead. Instead of enslaving brown people here, now our kinder gentler federal government just blow them up in foreign countries instead. )

>The reinterpretation of the Constitution that occurred during the Great Depression granted the federal government the authority to regulate commerce within States under the interstate commerce clause. This authority drives everything from farm subsidies to drug regulation.

That's the first time I've seen the war on drugs used to justify the centralization of power. I suppose we need a new civil war against the "untrustworthy" states that have legalized marijuana so affairs can be run the right way.

It's pretty "reasonable" to believe the federal government DOESN't need the authority they currently have.

There was another but we're still grappling with it. Nuclear weapons, and modern weaponry, the needs of real-time modern war, have transferred powers to the Executive that did not exist before in practice. It was never intended, after all, for the President to, semi-literally, have a button to press that ends the world. It arose dynamically out of a changing response to the needs of the early cold war, and has become effectively part of the unwritten constitution, without it ever really being explicitly considered how it should fit into the puzzle.

Your also forgetting the 16th amendment (federal income tax). This arguably was the critical aspect in increasing federal power.