Bernie bashers

Many of the folks in the Bernie Bashers crowd point out - correctly - that's there's little chance any of his policies could be implemented.
So what?

Maybe it's better to stake out extreme positions and accept moderate compromises when the time comes.

I recall that Obama came into office promising bipartisanship, and ALWAYS proposed sane, moderate positions as his starting points.
It didn't work.
The Republicans saw his willingness to be reasonable as weakness.

Maybe, just maybe, it's better to start out with WHAT YOU REALLY WANT!... then give a little in negotiations.

(This seems to be how Rubio is positioning himself as the "sane" alternative to Trump or Cruz! - "Hey, compared to THOSE guys, I'm not all that bat-shit crazy!")