The Senate is, while not the whole story, a significant part of the reason the government constantly fails to do what is either the desire of the people or what's in their interests. I wouldn't lament losing the Senate.
The US Senate is designed to check and balance the House of Representatives. But that often puts the Congress as a whole in deadlock, meaning it can no longer balance the other two branches.
When they could get anything done they delegated a lot of power to the Executive. Which worked ok, but eventually a "unitary executive" appropriated even more power, and the Legislature is powerless to prevent it.
Unpopular opinion: deadlock is fine. Most legislation is bad. What really matters is the budget. And the rule that failing to pass a budget can automatically force an election avoids the absurd US "shutdown" that isn't a shutdown.
This is now my second favorite idea, after a nationwide ban of first past the post voting schemes.
My third (previously second) is outlawing political parties. The problem with that one is it would be really difficult to implement in a way that doesn't run afoul of freedom of association and freedom of speech. Probably worth figuring out though.
Voting system reform would probably mitigate the worst aspects of political parties.
Egypt after ousting Mubarak held an election where a third of seats were reserved for independents. Most winning candidates were just Muslim Brotherhood affiliated. I suspect the military interim government did that deliberately to justify their later coup.
This is where the intra-party coalitions become important. Every party of significant size has them. Labour is effectively a coalition between a rightwing faction (New Labour/Blue Labour) and everyone else who is more leftwing. The internal and external debate is the question: should they focus "right" (immigrant and queerbashing, welfare cuts) to appease the right wing of the party and try to pick up Reform/Conservative voters, or focus "left" on their base and people who are switching to Green?
On the other hand, voting needs to mean something. If voting doesn't mean anything, because the whole system is held in a vice grip by a sclerotic institution playing power games with itself, then the broader system eventually collapses.
My personal opinion is that Mitch McConnell's intransigence and unwillingness to do anything lest Obama get credit for it led directly to an increased desire for a "strongman"
The Senate was fundamentally from the start a compromise in favor of the slave-owning ogliarchy. You just have to look at free and slave states being admitted in pairs to preserve the status quo of slavery to see how that went.
The Senate gives a rather disproportionate democracy in which the votes of a small number in small states take on disproportionate significance compared to the votes of a large number in populous states.
That still does nothing to refute the parent's complaint about democracy. Lopsided representation is still representation (as opposed to a council of nobles or military generals or whoever).
Also the thing you're objecting to is literally the entire point of the senate from day one. It was intended to give less populous states an equal voice in contrast to the house of representatives. Unfortunately history happened and the house of representatives hasn't been proportional for a long time. But if you're going to complain about something it should probably be the latter rather than the former.
