Sanders has a good chance of winning the Democratic primary if he chooses to run again, he's got high approval ratings, has developed the name recognition he lacked in 2016, and has built inroads with minority communities. His biggest opponent, if he decided to run, would be Joe Biden. But considering what happened in 2016, I think Sanders would garner a pretty big advantage going into the race, and I think each candidates records show for themselves. Biden spent 8 years as VP in a moderate Democratic administration. The momentum is currently with progressives like Sanders.
If you agree with Sanders political policies, don't be so petty to benefit the Republican party just because you disagree or dislike one of his supporters. That detrimentally affects minorities, women, the LGBT community, the poor, and middle class, and countless others.
Vote for who has the best political philosophy and supports the right positions