Aligning Ewan MacColl with 'extreme politics' doesn't ring true to me. He was a socialist. I don't recall any 'extreme politics' in his songwriting; as far as I'm aware he never called for anyone to be executed.

There were times when he was supportive of Mao's China and Stalin's Russia: like many on the left in the mid-20th Century, he was unaware of what lay behind those regimes (and like many on the left in the mid-20th Century, perhaps reluctant to face up to it).