Khan's campaign to retake London from Conservatives ran on pledges to build more affordable housing and halt rising public transit fares. He also distanced himself from the more left-leaning Labour leader Jeremy Corbyn.
Goldsmith's tactics were widely denounced as vicious and self-destructive, even by his fellow Conservatives.
Conservative politician Andrew Boff told the BBC, "It was effectively saying that people of conservative religious views are not to be trusted and you shouldn't share a platform with them. I mean, that's outrageous."
Labour managed to hang on to its territory in elections across the rest of England, even gaining ground in a few areas. The party didn't fare as well in Scotland, though; it's now behind both the Scottish National Party and the Conservatives.