Screaming into the wind? David Gilder / Shutterstock.com

Dana Houle in the The New Republic:

At this point, arguments about Bernie Sanders’s platform, his movement, or his purported electability are irrelevant; he will not be the Democratic nominee for president. Sanders must know this, but he has declared he will contest Clinton’s nomination up to the party’s nominating convention in July.

It is Sanders’s prerogative to remain in the race. But exercising that prerogative makes it easier for mega-wealthy conservatives to spend hundreds of millions of dollars to lethally bludgeon both Clinton’s candidacy and the progressive agenda to which Sanders has devoted his career. This is not solely about combating the grave threat of a Donald Trump presidency. It is also about the potential of a Democratic landslide and the progressive achievements that could follow, which is an opportunity too rare and precious to squander. The best way for Sanders to advance the progressive cause is to end his campaign and unabashedly ask his supporters to join him in helping to elect Hillary Clinton.

It's worth reading the whole thing, but in sum: the greater good of Democrats winning control of one house—or maybe both houses—of Congress far outweighs the lesser good of Bernie continuing on to the Philadelphia convention. In one instance, the party remains fractured until one or a few platform planks get changed by Bernie's supporters in Philadelphia. In the other instance, actual laws and policies move leftward on a scale not seen in a long time. Plus, as Houle points out, "a Clinton landslide would reverberate even further down the ballot." Houle continues:

Republican governors and legislators have blocked the Medicaid expansion, imposed regressive taxes, cut funding for education, attacked unions, obstructed efforts to deal with climate change, and led revanchist attacks on voting, LGBTQ, and reproductive rights—all key issues for Sanders. Flipping control of state governments could help stop agendas being advanced by the Kochs and social conservatives at the state level. It may even open up possibilities to implement the progressive policies Sanders holds dear.

In other words, ending his campaign now may now be the best way for Sanders to move political results in the directions he'd prefer.