Bernie Sanders' supporters are an immense asset.

Here are a few reasons why the Bernie Sanders campaign has an extraordinary asset in its supporters.

1. Sanders' supporters constitute a movement, not just a single campaign. Obama had a groundswell of support in 2008, but it was focused on him and his candidacy, not on policies and commitment to specific aims in the platform. Obama won because he united an anti-Bush Democratic party with a Bush-fatigued center, but once in office he lost the anti-Bush center almost immediately, because the Republicans fought Obama on every single move he made, and he looked weak (which he was, and strategically foolish to boot). And Trump is far, far worse than the Obama opposition of the pre-Trump Republican party, which was already hysterical. Trump isn't Bush. Dislodging him will require a movement, not just a single campaign. Or, a single campaign that manages to defeat Trump will nevertheless fail immediately under Republican opposition -- it will at best be another weak Democratic president who is an island to him or herself, hapless in the face of the nearly fascist opposition.
2. Sanders' voters are diverse. What's more, the reasons for this diversity are not just cultural and not just rooted in the ideology of culture wars (i.e. Sanders supporters aren't only liberals who are attracted to his stances on sexual rights, the futures of young people, and immigration). The Sanders campaign is saying things about labor that Democrats aren't used to saying anymore, and that working class voters aren't used to hearing anymore, and it diversifies his base: he talks far more than any other candidate about unions and a living wage, for starters. In an extraordinary article that I will be referring to for months to come ("The Color of Economic Anxiety"), the journalist Malaika Jabali wrote how utterly ignored black voters have been in the Midwest by Clinton and other Democrats, and what a priority it is for these voters that a candidate take their lives seriously -- particularly given high unemployment, the loss of manufacturing jobs, police abuses, and the legacy of segregation. A CBS News/YouGov poll in South Carolina of likely Democratic voters (published February 20, 2020) found that black voters ranked "economic issues, including topics like jobs and wages" as their number one issue. Sanders' steady and crystal-clear focus on the economic hardships of working people, compared to the astonishing wealth at the very top, is a major source of the diversity of his campaign. Don't expect to hear that view very frequently from many news outlets (they're more likely to focus on ambivalent swing voters, largely ones who are white), but statistics bear it out.  
3. Sanders supporters are angry. This is an asset for the obvious reason that there is so much to be angry about. Have you noticed how defeatist much of the Democratic party's base has become, given the extraordinary abuses of power coming out of the Trump presidency? The anger coming out of Democrats (politicians and voters both) often seems feckless to me -- it seems symbolic, focused on issues of civility, decorum, and process (which do indeed matter), and rooted in showing indignation. Chuck Schumer's anger against Trump is not a moral anger. It is not a burning anger. It is an anger born of intimidation and doubt. Democrats impeached Trump for a breach with process and decorum (which was outrageous), when they could have added articles of impeachment for his abandonment of Puerto Rico or the deaths of children in federal custody or his promoting of the treasonous QAnon or the illegal bombing of Syria. So when centrists and moderates say they're afraid of Sanders' anger, ask them in all sincerity why that anger is out of place, and mention in all sincerity the things that make you angry. If they say that it's because Sanders' anger will scare off moderates, well guess what -- they've already ceded that Sanders and his supporters are probably justified in their anger. Which means we shouldn't water down our anger against injustice and pick Buttigieg instead; we should work to remind the hapless and intimidated moderates how many things there are to be angry about. We should channel our anger because it is needed to fight Trump. Moderates do want to see Trump out of power, don't they?

There are scores of further ways to make the argument that the people supporting Bernie Sanders' campaign are not just an asset but that they constitute the only reasonable chance to both dislodge Trump and contest the hysterical, dirty Republican party that would remain after his presidency.

There are also some reasons to worry about Sanders' supporters, and it's important for me to articulate these as a supporter myself. Despite the defensive reaction that I know many Sanders supporters would have if they read this, I hope many of them can at least try to consider these arguments with an open mind. Conversely, it is only honest of us to acknowledge that some of our potential allies on the left, who don't yet support Sanders, may feel worried about the stances or behavior of some of his supporters. By the way, if you're not a Sanders supporter and you read these criticisms, that doesn't mean you're entitled to just copy and paste them somewhere else and say "See? Even some of Bernie's own voters think that his campaign is full of crazies!" -- not without acknowledging the flip-side of things as I tried to do above, namely that the very things you might criticize about Sanders' supporters may also be undeniable strengths in another sense.

I am writing about these in a separate article.