I don't want anyone from 9 to 15 (although i don't know McAuliffe and Patrick enough, and Klobuchar isn't "terrible", but not great either). Warren has no chance. I don't want Booker and Biden either (although Booker is in favour of legalizing weed, which is a big pro to me). I have my doubts over Gillibrand and Brown too. Is Brown really a progressive? To me, it's clear. Sanders and O'Rourke are the best candidates. Harris is okay too, but i'll need a guarantee that she's progressive enough, and doesn't flip flop all the time on issues, and she'll have to explain her controversy about Mnuchin.
Are you really doubting Brown's progressive bonafides while supporting O'Rourke who was a member of the New Democrats caucus?
O'Rourke today is probably the most far-left candidate out there. Running of Medicare-for-all, abolishing ICE, No PAC money along with positions like impeaching Trump. In 2018, O'Rourke is to the left of Sanders & Warren & Brown !
That said a losing Senate candidate has no chance. In a 100 years, a House Member to President has not happened !