Before we jump to conclusions, we need to see basically the 2020 exit polls and see if these people are actually becoming more Republican. Or the 2018 ones. It could be that a lot of high schoolers are Republicans and then vote Democratic in college and establish a Democratic pattern.
Also what's the history for this poll? Is it reputable?
How many other 18-34 year olds flirted with Nationalism at age 16 and 17? There has always been a lot of what would become the alt-Right on Final Fantasy forums. In a way, Trump's election was my expirence between 2001 and 2003 coming back to remind me of the old days. I grew out of that crowd just before Pepe became a thing for anyone.
I know nothing about their experiences honestly. I know that young white people were nowhere as radically Republican as this group. They voted 47-43% Trump which is a far cry from the Bush era. Obama also has a 44-30% approval rating in this group, which is interesting.