The problem of population in high-energy societies is not a problem of excessive birth rates: Every single modern society has low birth rates, some of them 40% lower than that needed just to stabilize population. The problem that prosperous societies in the U.S. and Europe face is immigration from poor countries.

Neither Democrat nor Republican leaders have the guts to do what needs to be done, because both are captive to special-interest groups that favor large-scale immigration to the U.S. Note that this failure of democracy is a VBD (Very Big Deal), because even though a large majority of U.S. voters want immigration stopped (or greatly restricted), the people have been betrayed by their elected representives.

IMO, the leaderships of the Republican and Democratic parties are both morally and intellectually bankrupt. The major parties are broken and cannot be fixed, and hence the importance of creating a successful new party for the first time in a hundred and fifty years.