Sanders still naive about the Democratic Party

See Sanders' latest speech below. Therein he says that he'll work with Clinton to defeat Trump. But he'll also not concede until the convention because he wants to reform the Democratic Party platform to include our progressive agenda. It's time the Party worked for we the people again instead of its wealthiest constituents. I admire that Sanders is trying to reform a corrupt Party. And they will undoubtedly make progressive concessions at the convention. But he will learn that it's only for show to get the progressive vote, and they'll ignore those concessions going forward. And apparently that's what it's going to take for him to finally give up on the Party and direct his movement toward an alternative progressive Party and/or join the Green Party.