From the article:

“Should we be supporting Independent candidates who are prepared to take on both parties?”

[Sanders’s question] was also influenced by the campaign of former union leader Dan Osborn, who ran this fall as a working-class independent in the deep-red state of Nebraska.

Against an entrenched Republican incumbent, and without big money backing or party support, Osborn shocked pundits by winning 47 percent of the vote.

Bernie Sanders: I think that what Dan Osborn did should be looked at as a model for the future. He took on both political parties. He took on the corporate world. He ran as a strong trade unionist. Without party support, getting heavily outspent, he got through to working-class people all over Nebraska.

It sounds like you can still get pretty far by just addressing the actual concerns of the working class and offering real solutions to problems. Still an uphill battle, definitely, but maybe not an insurmountable climb.