I believe that the "reasoning" behind the change to popularly elected Senators was exactly that: to "enhance" that glorious thing called "democracy." After all, who could possibly argue against each person having a direct vote on everything? Democracy, right?
This was directly opposite to what the original Congress saw as a valuable check against the inherent evils of a pure democracy.
Democracy is doomed from the moment the voters discover that they can vote to get largesse from the public treasury. (I won't put quotes around that because I don't remember who said it, or if it's exact.)