Ronald Reagan came third in the 1968 Republican primary, didn't run in 1972, and came second in 1976. If you were writing this in the late 1970s you'd be arguing that Ronald Reagan was wildly unpopular because he'd never won a single primary despite running for president twice. Whatever you think of his legacy (and I think he's responsible for a lot of the worst parts of the last half century) he was wildly popular as president.

Was Harris popular? Not especially. But, the issue wasn't her laugh. Aside from being non-white and non-male, she was also running as a pro-establishment candidate at a very anti-establishment time. Trump's absolute destruction of the establishment will go down as history as the point at which the US really started to self-destruct. It shows how good the status quo actually was for a lot of things Americans take for granted. But, the message that "everything is fine, I'm just going to continue with existing policies" was the absolute wrong one to use.