At this point in the campaign, Bernie Sanders has three potential routes to take, each with implications for this election cycle, the Democratic Party and his own legacy.
In no particular order, here are his options as I see them:
Route #1: Quit
This is doubtful and very unlikely, but an option none the less. He could calculate that at this point he made his point and it's time to ensure Republucan defeat.
Route #2: Stay in the race but focus on his platform and pivot from attacking Clinton.
Sanders has a dwindling amount of spotlight left and could do the country a favor by pushing the needle left with pointed conversations about why his ideas would make this country better. By focusing more on educating the electorate about single payor and income inequality etc and less on Clintons paid speeches and judgement, Bernie could ensure his legacy is one of positivity and progressive ideals. Sanders could use this moment to remove the stigma of socialist based ideas and allow future leaders and generations to benifit from his decades of work.
Route #3: Scorched earth
If he chooses, Bernie could go all in and bloody up his opponent to the point where her general election prospects are jeopardized. He continue to perpetuate disingenous right wing talking points and not speak out against the Bernie or bust movement and help the republicans gain the White House in the fall. We know that Bernie’s die hards have dug their heels in and claim they will not support the nominee if it is not him. Bernie can allow that type of idealism to persist or he could choose not too. It will be up to Sanders to make that judgement.