1,529 delegates. That’s how many delegates Sanders is projected to have on June 6th after the US Virgin Islands holds its primary. The 2020 Democratic National Convention begins 37 days later on Monday, July 13.
1,990 delegates are required to obtain a majority and Sanders will be the only one anywhere near that number. So if Democrats want to beat Trump and have a unified party gong into the fall election everyone running who is not Bernie Sanders needs to drop out now and support the eventual nominee.
Either that or you are working for Putin. Be practical, support Bernie.