I've often listened to him and George Galloway
Galloway is just straightforwardly anti-Semitic.
In Livingstone's case, as I've said elsewhere, he appears to be a man in his seventies showing obvious early signs of dementia. He probably always thought these things, but was smart enough to shut up about them. Over on "Relationships", a common question when people's ageing parents start to become unusually aggressive or difficult is to get dementia screening, as the loss of that filter between your first thought and your first words spoken is an early symptom. This is the second time: the row he got into over calling people "mentally unwell" had the same tendency: a throwaway comment on local radio that he was unable to row back and just pushed on blindly, digging a deeper and deeper hole for himself.
Is Livingstone an anti-Semitic holocaust apologist? Probably not, although he's too relaxed about people who are. What he is, however, is an auto-didact with the auto-didact's confidence in their limited reading of tertiary sources, and filtering of those to match their preconceptions. I once heard a skinhead on a train giving his friend a history of the middle East (the punchline, of course, being that the Jews control the world) which had that property we now call truthiness. He was able to cite all sorts of agreements and events which it would take a semester to explain, a lifetime to understand, of which his audience knew nothing. The speaker knew almost nothing as well, but was able to give a fluent account untroubled by nuance or context, which sounded superficially convincing. I'd be willing to be convinced that Livingstone doesn't really idolise Hitler (although claiming that there's a "before" and "after" "going mad" about the holocaust is straight from the Irving playbook which admits the holocaust but claims Hitler, proud and upright, didn't have anything to do with it and that it was a Thomas-a-Beckett type over-delivery by his insubordinate subordinates) but he simply doesn't have the intellectual skills to make his point clearly enough to engage with.
Hitler stated repeatedly, in Mein Kampf and elsewhere, that the demand for a Jewish homeland in Palestine was a dishonest attempt by world Jewry to obtain a base for later plots and schemes. There was a half-hearted scheme to deport Jews to Palestine if they left all their belongings behind, but it was only the British victory at El Alamein which stopped the Nazis from moving into Palestine, as they had moved into Russia, systematically killing Jews. So those that might, in Livingstone's telling, might have escaped in 1932 would have been killed in 1941 without the intervention of the British 8th Army.
Coming next: Franz Rademacher was a proto-Zionist, because he only wanted to deport Jews to Madagascar.