US President Joe Biden on Wednesday took a harsh swipe at Russian President Vladimir Putin at an election rally in the western state of California. During a speech in San Francisco on Wednesday evening, Biden referred to the Russian president as a “crazy SOB,” according to members of the press travelling with him – the abbreviation “SOB” stands for “son of a bitch.” Biden was talking about climate change as an existential threat to humanity to a small group of campaign donors when he made the comment, only mentioning Putin in passing. “This is the last existential threat, it is climate. We hav…