I agree that pre-17th amendment, the Senate was not a Democratic (in the political representation sense, not the modern Progressive party sense) place. But, And? It wasn't perfect, but at least there was some checks and balances between the democratic impulses of the House and the aristocracy of the Presidency. Give the states a vote of whether they should have to pay for half of Medicaid for instance. Or fight back when it comes to spending on highways and trying to avoid the strings that always come attached (raising the drinking age, lowering the speed limit, etc.)
Via Volokh with comments