Earlier quoted context omitted.
Two houses helps prevent tyranny of the majority. Consider the United States. Each state gets 2 senators no matter what, but the proportion of House of Representatives seats each state gets is calculated based on the state's population. This quirk means that even small states like Wyoming have equal Senate representation as the populous states like California, Texas or New York. This arguably undemocratic over-repres…
unfortunately such situations often degenerate into a tyranny of the minority, the UK house of lords as a mechanism for the aristocracy to keep holding power with a veneer of democracy is a good example, which is why it has steadily lost political legitimacy through time. I don't think there is good evidence that the senate has in fact made the USA stronger as a nation, the only thing I have ever seen on the topic is…
The key thing is if one party wants to be able to pass the larger number without that pivotal vote, they need to appeal to a greater fraction of society and win more seats so they don't require that particular vote.