Clinton has not closed the deal with Sanders supporters
Nearly Half of Sanders Supporters Won't Support ClintonThe Democrats appear to be having as much trouble as Trump in consolidating support from former revivals. That is what happens when both parties choose someone who a significant portion of voters does not trust. It is also why the polling puts both candidates in the low 40's at this stage.
The Vermont senator says he'll work to defeat Trump, but has yet to endorse the presumptive Democratic presidential nominee.