I wouldn’t get all that wound up about bloodlines. That’s the stuff Royals do. The closest we have to that are Kennedys, and it’s obvious the longer the line, the weaker the gene pool.
So what if Ronald Reagan had no grandkids? Somebody else will, or has. Like Sarah Palin’s grandparents.
2008, Caucasian, aged 45-49 years: 15.964 millionThat's a decline of about 30% [and increasing] since the end of the "Baby Boom".
2008, Caucasian, aged 40-44 years: 14.085 million
2008, Caucasian, aged 35-39 years: 12.981 million
2008, Caucasian, aged 30-34 years: 11.456 million
2008, Caucasian, aged 25-29 years: 12.740 million
2008, Caucasian, aged 20-24 years: 12.949 million
2008, Caucasian, aged 15-19 years: 12.903 million
2008, Caucasian, aged 10-14 years: 11.660 million
2008, Caucasian, aged 05-09 years: 11.222 million
2008, Caucasian, aged 00-04 years: 11.065 million