81% already had in June according to this poll.
dailykos.com/story/2016/6/26/1542650/-Bad-news-for-Trump-ABC-WaPo-poll-81-of-Sanders-backers-have-rallied-to-Hillary-already
I was one of them. But in an email yesterday to those of us who supported him he wrote…
“In terms of the presidential election this November, there is no doubt that the election of Donald Trump as president would be a devastating blow to all that we are fighting for. To have all of the work we have done in elevating our progressive ideals be dashed away by a complete Republican takeover of Washington… would be unthinkable”
“Today, I endorsed Hillary Clinton to be our next president. I know that some of you will be disappointed with that decision. But I believe that, at this moment, our country, our values, and our common vision for a transformed America, are best served by the defeat of Donald Trump and the election of Hillary Clinton.”
“In the weeks since the last primary, both campaigns have worked together in good faith to bridge some of the policy issues that divided us during the election. Did we come to agreement on everything? Of course not. But we made important steps forward.”
He then went on to list their agreement on a college plan for working families. A public healthcare option. $15 minimum wage and he listed many other areas.
He added, “but none of these initiatives will happen if we do not elect a Democratic president in November. None! In fact, we will go backward.”