While it is tempting to focus on a single reason why Harris lost, her defeat was due to the combined effects of various factors ranging from the large to the miniscule. In the run up to the election, Trump supporters posted relentlessly on social media that gas and groceries were cheaper under Trump, and many seem to have voted for Trump to punish Harris and Biden for their economic situation. Harris has also been criticized for being locked into the status quo and was perceived as being a mere continuation of the unpopular Biden presidency and Trump has been able to convey the impression that he will shake things up and damage the status quo, which proved appealing. Running as a moderate centrist who might make a few minor tweaks was not, it turns out, a winning strategy for Harris. Voters correctly believe they are being harmed by the status quo, but their only viable alternatives were voting for someone already presiding over their suffering or for Trump.
It is certainly reasonable to consider the impact of sexism and racism, subconscious or otherwise. As the polls noted, Trump did very well with men, while Harris did well with women (but not well enough). While young men are not a huge demographic, the Democrats seem to be losing the culture war for them. For example, in the popular culture realms of video games, movies and shows, social media influencers have been successful in advancing the narrative that games, shows and movies are bad because they are “woke” (anti-male and anti-white). Other influencers that target young men also tend to be on the right. These culture war victories no doubt helped Trump, especially since the Democrats do not seem inclined to engage much in trying to win that demographic.
An obvious reason why Harris lost is that she was running against Trump. To use a slightly out of date Halloween metaphor, Trump is like a werewolf in that he seems immune to things that would destroy mere humans. For other politicians, a scandal or engaging in weird behavior would end their career, but Trump has proven largely immune to consequences. In a real sense, nothing Trump did had any negative impact on his support. If Harris had been running against anyone else who did what Trump did or acted like him, she would have almost certainly won by a landslide by simply pointing out the scandals, crimes and weird behavior. But she was running against Trump and thus none of this harmed him. For Democrats, their best hope is that no other Republican has Trump’s magical immunity.
Lastly, there is the rhetorical advantage held by Trump. Trump and his supporters fully embraced lying as a strategy, advancing lies about the 2020 election, about Harris, about immigration and anything else they could think of. The “fire hose of falsehood” is almost impossible to defeat with the truth, especially if the lies are repeated across news media and social media. Trump also had an advantage in his focus on negative emotions, such as anger and fear. As a matter of psychology, people weigh the negative more heavily than the positive and this fuels various powerful fallacies and rhetorical devices. While hope and change can win, fear and anger win more often. This focus on lying and negative emotions provides Republicans with a strong rhetorical advantage which Democrats will be hard pressed to counter.
Though I am not American, and I believe that America is a great country, and the most powerful in the world, I offer an additional (hypothetical) reason as to why Harris lost: most people (not just Americans) are like Trump, i.e. they don’t really care about Ukraine, or what is better for all, but only what’s better for themselves. Plato already gave this as a powerful reason why he didn’t believe in democracy. And I agree with him.
Just old human selfishness, which dictates that whatever is good in the short term for me, not later for all, is better, which is why Trump doesn’t care about climate change either.
But what really astonishes me is that someone like him, who strikes one as being very far from being an intellectual, becomes president of the United States, and twice, for good measure. Incredible, really. Just like you said: like a werewolf who’s immune to whatever kills humans, pretty much literally.