The correct answer to this open question is the following.
It should be better that Congress could respond more closely to the will of the people. However, I think that the current arrangement of a House of Representatives and a Senate provides the right mix of responsiveness and deliberation.
What I mean is that the problem is not in the structure of teh Senate or the House of Representatives, that of course, always have the potential to be improved to make it more efficient.
The key issue here is not in the structure but in people. In this case, in legislators.
I said this because, in past and recent times, we have seen how Political Action Committees (PACS) or interest groups have hired lobbyists to negotiate with Congressmen in other to get favorable legislation approved that benefit their private interests. And that is not the reason why Congressmen were elected by the American people.
On the contrary, legislators were elected to serve US citizens and resolve their many concerns such as employee, security, health services, and more.