Leave the name-calling out--it just reveals that you're not able to discuss this rationally.
who unfortunately has succumbed to some pretty weird ideas in his old age
How can you make such an inappropriate comment? It's suitable for politics, not supposedly rational discussion.
It's really simple, if you look at it from the point of view of stochastic search algorithms. If you significantly weaken selection pressure (as we've done and will continue to do increasingly) while mutation and crossover continue to randomize the gene pool, the average fitness of a population by any given metric will fall over time (because the gene pool is very far from random, and individuals are on average closer to some (local) maximum of the current fitness function than a set random samples would be). There's just no way around it. If there's no natural selection, then there's a clear case to be made for artificial selection. I equate eugenics with selective breeding in the most general sense. It doesn't require genocide, and it doesn't require preventing anyone from reproducing -- it only requires encouraging reproduction for some portion of the population. While that still is distasteful for some, I'm still waiting for an alternative proposal for the very long term.