I think it would decrease Clinton's chances of winning.
Warren is probably too liberal.
Imagine a Christie/Cruz ticket, only on the left.
I do not know what you mean by a Christie/Cruz ticket, only on the left; the two strike me as counter balances; are you saying that sort of balanced ticket is a winner? I presume that you are.
If you are saying that, I disagree somewhat. Here is why.
If you're running in the GOP you have to practice some deception and cater to the right from January-July then pivot to the middle from August to November. Either you're BSing the voters in the Spring or the Fall.
The Dems don't have such a problem with the pivot because they are able to run as moderates without having to cater to extreme planks of their party.
Personally, I think it is because the radical gay rights activists are just flat out more sophisticated than the radical Christian right activists...so the left wing hardliners are content staying quiet and letting the candidates be politicians, not popes.
There is such a thing as too liberal (even for my tastes) but I don't think Clinton/Warren puts you there necessarily.