Earlier quoted context omitted.
You can have federalism without anti-democratic institutions like the Senate. If the Senate was abolished or starting apportioning senators by population, the US would remain federalist, because there'd still be plenty of powers devolved to the states. That's what makes it federalist.
No, you can't. The only way you can truly prevent states from having their interests overriden by a majority of the nation is to give them a direct role in the legislative process. Democracy is three wolves and two sheep voting on what to have for dinner. It's last thing we want. So when the three wolves invite the two sheep to join them in a democracy, the sheep wisely say "Not a democracy, but a federal union, with…
The voting blocs aren’t between small states and large states, those basically don’t and haven’t existed for a long time. The senate is not a moderating body; the founders entirely failed to account for political parties.
The constitution isn’t a suicide pact, the founders lived in a completely different world, and it’s very apparent that the US federal government system is dysfunctional and failing.
The US legislature is designed to not do much, especially with the filibuster. Which is a huge problem when there are a succession of crises that the legislature has failed to address.