The population of the United States is 327 million and according to the internet about 61.3 Percent is white. That means that about 201 million are white, non-Hispanic and about 127 million are minorities. Of those 201 million white, non-Hispanic about 20 Percent are in their twenties which would be about 41 million, leaving about 161 million.
About 70 Percent of the 161 million whites will vote Republican, 70 percent of minorities will vote Democrat and 80 Percent of the 20 year olds will vote Democratic
That means that the Republicans would get about 159 million votes and the Democrats would get about 233 million votes