There is a movement. The Democrats have been forced to shift to the left, on economic issues, which naturally feels like a threat to Dem insiders as well as centrists of all political persuasions. There will be a consistent parade of folks like Comey, warning of the dangers of economically progressive ideas and policies. These will generally be people with privilege but not imagination.
A better idea? Join Democratic Socialists of America and work for solidarity and a fair shot for all Americans. =)