Of those three, I'd say Masto is the likeliest. Even then, though, that would make an all-Western ticket, which may not be very viable in a general election. Moulton wouldn't be bad, but I don't think having two straight, Christian, white guys on the ticket isn't going to do much excite the Democratic base. I think Tammy Baldwin would be a good fit for Merkley.
Seconded. Midwestern, liked by the progressive wing but not super alienating to moderates.
