In 2024 Trump got some of the youth vote, still not a majority. Trump never won Gen X (or at least Millennial) and below.

So the prediction sounds right? The Republicans have burnt the youth vote pretty badly and have never really recovered.

In the 2024 election, Trump's strongest margins appear to have been with Gen X, where he was roughly +10% over Harris, even stronger than his results among the Baby Boomers.

(See, e.g. https://www.pewresearch.org/politics/2025/06/26/voting-patte... and https://www.nbcnews.com/politics/2024-elections/exit-polls. Annoyingly, the polls don't cleanly break down into generations; Gen X would be the ~44-60 crowd for that election.)