The Democratic Party had a chance to keep them in the fold but they blew it.
No amount of threats of Republican takeover will change the direction the Left is going. If the Republicans take over the House, Senate, and the White House, then so be it. The alarm bells no longer work. The fear-mongering from the centrists will fall on deaf ears.
They have not left their Party - their Party has left them.
Most Democrats do not want to hear this and refuse to accept that it will happen. After all, anything is better than having the Republicans in total control. Well, no, it isn't .
It is worse to be deserted by your own Party. It is worse to have your ideals destroyed and replaced by Republican ideals. Winning the next election is no longer the most important thing for these beaten-down supporters of the Democratic Party.
If you think this is only a lone voice expressing dissatisfaction with the Party and , in the end, we will all unite behind Hillary to keep the White House, I think you are tragically mistaken.
The Democratic Left will either take back the Democratic Party or they will start their own Party. They will suffer no more under the illusion of being represented by the Democratic politicians in Washington.