Lots more good stuff with citations in the article, but this bit really ties it all together:

The right-wing obsession over racial demographics becomes obvious in the “pro-natalism” movement, which advocates for conservatives to have more children to take control of society. The mission of the movement is “to build an army of like-minded people, starting with their own children, who will reject a whole host of changes wrought by liberal democracy,” according to a fascinating recent story in Politico.

For the right wing, pro-natalism means looking for every possible means to increase the white percentage of the nation’s population. Through this lens, it’s not hard to see why Republicans remain virulently anti-immigration and strictly opposed to abortion.

Those two issues may appear unrelated, but in fact Republican positions on both stem at least in part from white demographic fears. Republicans want to halt the rise in the nonwhite population by curbing immigration. At the same time, they hope their abortion bans will boost domestic birth rates — staving off white demographic decline. They also want to ban contraceptives and no-fault divorce, forcing women to stay in marriages and have more children.

The Republican Party’s white nationalism is often justified in religious terms, since much of this agenda designed to enhance white power stems from the party’s Christian fundamentalist base. Along with Protestant evangelicals, the Republican religious base now includes fundamentalist Catholics, who stridently oppose abortion.