That is why the US government is designed the way it is, with the electoral college, 2 senators per state, etc.

It is all designed to prevent European style tyranny of the majority or mob rule, yet also create a representational state. It's a tricky balance. But our ancestors were, again, murdered or forced to flee half way around the world, so a core concern/reality we work hard to avoid at the cost of slower government/less direct democracy that like you say can change on a whim or easily be directed as a weapon against ones neighbors. We prefer a slow out of touch government that protects freedom/peoples rights than a government that represents short term opinion happy to trample.

My point was that an oppressive government cannot appear out of nowhere in a free country. The citizens must abandon constitutional values first. If an oppressive government remains in power and maintains its popularity long enough, it will infiltrate all levels of the government and compromise checks and balances.

Then, with popular and institutional support, the government can do basically whatever it wants. Regardless of what powers it had before or what the constitution says.

You should not be afraid of giving the government new powers simply because it might go bad later. (There are other valid reasons, but that's not one of them.) If the government does go bad, it can take those powers on its own just fine. You should be afraid of your fellow citizens going bad and starting to think that their personal goals and values are more important than constitutional values. Because that's a prerequisite for the government going bad.