I'm no fan of Corbyn but there was a politically motivated character assassination leading up to the election, where all major newspapers reported him and his party for anti-Semitism. The media all parroting lines fed by the Government with no critical analysis is complicit in Tories, and whoever wants to play the dirtiest, to remain in power and do whatever they want.
The naive elector sees Corbyn pissing off the Jewish groups on front pages everywhere, and or course they do not want to associate with people of that ilk. The majority trust newspapers and politicians too much, so get routinely played like a fiddle, and the best liar always wins.
The similar shit show is going to play out next election with Reform UK if the liar extraordinaire Nigel Farage decides to front it.