Hi , Above is the percentage of the age demographics for voter registration. I am sure if we looked at some racial groups , there would be differences there.
Any increase in turnout driven by increased registration will favour the democrats. ''Find me 18000 votes'' , suddenly becomes 36000 , if 18000 extra Swifties register in Georgia.
So relatively small movements in the battlegrounds , may allow celebs to have a disproportionate effect. It may also be that this effect may be greater than in the past, because of the amplification effect of social media.