I understand and it's my contention as well as that of every pundit and talking head that we will. For the Dems to win the Senate back, they'd need to win 8 out of 10 open seats. No one, not even bill clinton and terry mcauliffe are predicting that.
I'm not just talking about keeping the Democrats from winning back the Senate. I am saying that I can only support replacing a Republican with a Democrat (which is what you advocate) if the Republicans are going to pick up additional seats.