Which Democrat will be the best Presidential Candidate against the Crazy Right Wing Republicans?

http://www.alternet.org/election-2016/big-q-dem-debates-whos-most-effective-candidate-take-increasingly-insane-gop?akid=13569.294211.rrskFp&rd=1&src=newsletter1043972&t=6

The Big Q for the Dem Debates: Who's the Most Effective Candidate to Take on the Increasingly Insane GOP?

Who's going to persuade voters?