For Bernie supporters it's all about his policies. And his consistency and integrity.
So, the challenge becomes getting the word out about his policies. Because when people hear them as above and attach them to his campaign for POTUS, they become supporters.
Though sometimes it's not as easy as it sounds because people have a filter which
at times prevents them from even recognizing their own interests.
Bernie talks about it often. Usually within the context of working class republicans in red states who consistently vote against their own best interests due to divisive wedge issues such as abortion and gay rights.
Working class republicans are not the only ones guilty of voting against their best interests. It's prevalent among those who have a difficult time envisioning a change in the status quo, even if the status quo is an unsustainable economic and environmental disaster in the making.