I've got your alt-right right here: 0.43%

LOL: Richard Spencer imagines 6-9% of US population is effectively alt-right, a vanguard just waiting for support from many multiples of that

Time for a Lenin haircut.

Meanwhile minimum 10% of US population directly allied with already socialist military, then add Pentagon's industrial complex and finally 79.5 million owner-occupied housing units, all just waiting for The Right Man to come along and end it all.

Little-reported story about 2016 election survey found 38% of whites expressed strong feelings of white solidarity

The Demography of the Alt-Right:

The survey included 3,038 non-Hispanic white respondents. Among these respondents, only a minority expressed high values on any of the above questions: about 28% expressed strong feelings of white identity; about 38% expressed strong feelings of white solidarity; and about 27% felt that whites suffer a meaningful amount of discrimination in American life. A much smaller minority, about 6% of respondents, expressed all three opinions. It is worth noting that a 2017Washington Post-ABC News poll estimated that about 10% of respondents supported the Alt-Right.

In other words, the alt-right has a lot of work to do if it's going to convince the other 62% of whites to embrace their white identity.

On the other hand, the civilian non institutional white population in 2016 averaged 198.215 million people, 38% of which is 75.3 million "white aware" Americans.