I am not familiar with the demographics of other countries, but in Spain, Vox is quite popular amongst the young people. Old people tend to be very loyal to "their" party and keep voting PP, even though they agree with Vox's main talking points.

The younger voters are indeed pushing fascism, at least in Spain. I had also assumed ultraconservative, nationalist movements would be more popular with the older demographic in Spain but, proving my point that it's those who didn't experience Franco's dictatorship who are buying into the far-right ideals, Vox voters are on average 8 years younger than voters of other parties in the country (apologies for the link to Spanish media).

I don't know if this is any different in other countries but in Spain the people swallowing the fascist pill are very much your archetypical white, privileged, young male.