In my blog posting, "Mr. Collins Makes It All Quite Clear," I outline how the system works. "Donors," not "voters," get represented.
It's not a party thing, either. Collins is a Republican. Menendez is a Democrat, and a November 26th article from AlterNet focuses specifically on the Democrats, as it talks about this phenomenon in connection with a so-called "tax reform" bill, now being advanced in Congress. This is a bill that would benefit the extremely rich, at the expense of everyone else, and if the bill passes (as seems quite possible), Democrats, as well as Republicans, will have been implicated in this failure to represent the public interest.
I think it has to be up to us.