Rome. When congress is powerless for years, and bad things start happening, congress will give all of its power to the executive branch, and be cheered for doing so. Phase two is the executive selecting their own successor. I don't think Rome was ever a brutal dictatorship, but it turned into something like a monarchy.

It's not a thing that'll happen today, or perhaps even in five hundred years, but that's the historical flight plan. We're obviously structured for the executive branch to soak up all the power, eventually. (at least it has so far) The executive branch has pretty much completely taken the power of declaring war.

Congress can't really pass a budget any more. i kinda think in the next 50 years they'll give up that power and just rubber stamp whatever the executive throws at them.