Reagan Democrat is a generic term for rust belt blue collar forgotten people. Has nothing to do with age.
Every year the white birth rate goes down. Today it's the lowest of the four main ethnic groups in the country. Every year white working class voters get older. That's just a fact. Take a look at Reagan's 2 victories. +10% popular vote in 1980. +18% in 1984 with 525 EVs.
Republicans won 3 times in the last 5 tries for the White House, but in 2 of those 3, including 2016, we couldn't swing the popular vote.
In 1984 Regan won Texas with 63.6% of the vote. In 2012 that margin was down to 57.17%. In the 2016, 52%. Trump won by 36 EVs. Texas awards 38 EVs. See where were going?
Given those demographics, I'm not so sure that calling fellow Republicans traitors and agitating for their removal from the party is a winning strategy.