Harold Meyerson’s Washington Post column, “Can Bernie Sanders’s followers create a true leftist movement?” puts his campaign in perspective and outlines the challenge that awaits his followers:

Bernie Sanders’s presidential campaign is different. He has refused to establish a super PAC. He shuns personal attacks. And, not incidentally, he proclaims himself a democratic socialist.
But there’s one further way in which his campaign fundamentally differs not just from those of the other candidates but also from any in many years: While striving to win votes, it also has to morph into an enduring left-wing movement.
..Every period of progressive reform in U.S. history has come as a result of massive street heat, of energized movements that push policymaking elites to the left. Abolitionists pressured the Lincoln Republicans toward a policy of emancipation. Militant workers and a socialist left, whose general strikes shut down several major cities in 1934, prompted Franklin D. Roosevelt’s Democrats to legalize collective bargaining and create Social Security in 1935. The civil rights movement enabled the Kennedy-Johnson Democrats to pass the landmark legislation of the ’60s. Progressive reform doesn’t happen absent a large and vibrant left.

Regarding the Sanders campaign’s longer-term prospects, Meyerson writes:

…Precisely because Sanders has staked out the most distinctly leftist terrain of any major candidate in decades, and because so many Americans (young Americans in particular) have rallied to his cause, his campaign holds the promise of recreating that missing left…Well, maybe.
…The question that looms before the campaign is less whether it can win Sanders the Democratic nomination, much less the presidency — goals that look, to put it mildly, daunting. Rather, it is whether its volunteers can help form an enduring left movement without which a future Democratic president and Congress won’t be able to enact even minor changes to income distribution or minor reforms to a capitalism that erodes the middle class.

Meyerson cautions, “Problem is, progressive presidential candidacies seldom have consequential afterlives,” and offers the examples of presidential campaigns of Jesse Jackson in the 1980s and Robert LaFollette in 1924. Ditto, to some extent, for Henry Wallace in 1948. Nor did President Obama’s followers create much of a post-campaign movement of consequence. Looking toward the future, Meyerson adds:

…This formidable task requires, first, that Sanders’s legions understand the unique historic opportunity that their coming together presents: That their victory in all probability won’t be putting Bernie in the White House, but creating a surging and enduring left. That, in turn, requires them to give as much thought to forming or joining autonomous post-campaign organizations, and envisioning post-campaign mobilizations, as they now do to advancing Sanders’s candidacy..signing on for Sanders, if his volunteers are serious, isn’t like signing on for any other candidate. It should mean they’re signing on for rebuilding the long-gone American left.

Meyerson concludes, “Is this difficult? And how. Is this necessary? Totally.”
The impressive accomplishments of the Sanders campaign include taking the boogeyman out of the term “democratic socialism,” at least for a while, and forcing the MSM to report on some of the extraordinary achievements of democratic socialism in north European countries. What has been interesting about this, is how utterly limp the conservative response has been — pretty much reduced to leaden neo-Mccarthyist one-liners. I guess it’s hard to put down popular reforms like free college education and universal health care.
Along with Elizabeth Warren, Sanders’s fearless advocacy of economic justice reforms has pushed Hillary Clinton to the left, which may prove to be his most enduring contribution. If she wins, Sanders campaign supporters will have the responsibility of providing the leadership needed to secure her follow-through commitment.
Win or lose, Sanders has done a great thing. But Meyerson is right about the cause that beckons his followers and all progressive Democrats to an even more exciting future — a vibrant, well-rooted movement for democratic socialist reforms.