Bernie took on corrupt interests unlike any other Dem candidate in my life. Yet he refused to confront the national security establishment when it targeted him. This element would have sabotaged his presidency from within - after he let it in the building. https://thegrayzone.com/2020/02/24/the-russiagate-racket-targets-the-bernie-sanders-surge/

Bernie ran as a socialist but surrounded himself with foreign policy advisors from the Beltway think tank world. They had no desire to scuttle future opportunities by confronting their colleagues. And the candidate's anti-communist instincts helped keep him in line with them.