I think Trump's gains with young men are the main area patching him back up and are what's mostly being missed when people ask how it's this close.

While it's true that Younger Generations are getting more Liberal, that trend is only extremely strong among women. It's a weak trend among men(and it really only works if you compare them directly to like, Boomers). Gen X males have been gradually shifting right compared to the Obama years, and Gen Z is just broadly more right wing than Millennials. Gender may legitimately be the biggest divider right now, only rivaled by Urban Rural.

Rural Male Gen Z isn't as left as many people would think.

These gains(plus slow steady gains among Latino blocs, mostly Cubans and old blood Tejano types) are making up for the losses in women voters he suffered in 2022 and 2016 and the loss in black voters thanks to Harris.

That and the right wing is slowly clawing back control of portions of the media. In the Aftermath of Gamergate most of the mainstream internet platforms swung hard to the left and several became fully controlled like Twitter and Tumblr. Thanks in part to several tech bro defections and bot operations places like Facebook slipped in 2020 and now Twitter and CNN follow. That was keeping most of the bitter young men who weren't involved in GG or Republicans prior in line with the democrats. With that control erroding they're starting to slip. We've seen this playout in South Korea before, who's gender political divide is among the nastiest worldwide among democracies.