I think Ryan Avent is thinking too hard here:
What’s the right amount of democracy? Progressives have become increasingly incensed at the anti-majoritarian rules of the Senate, which seem specially designed to avert popular, and often sensible, progressive legislation. On the other hand: ballot initiatives.
The answer is representative government. What the Senate does is combine an unrepresentative system of election with an arbitrary bias toward the status quo. And it’s not merely the filibuster — bicameralism plus committees is already a lot of veto points.