The article is too complacent about America.
"America" is indeed at 2.1 fertility - bare replacement rate.
But drill one layer deeper.
American WHITES have a fertility rate of 1.8, well below replacement. American blacks are at 2.0, ALSO below replacement. It is American Hispanics, and only them in any appreciable numbers, with their 2.45 fertility rate, who drag the American birth figures up to replacement rates.
What is happening below the level of "America" generically, WITHIN America, is that Hispanics are replacing the white and black population at about the same rate that Muslims are replacing the white European population.
So, the future of Europe will probably be Sharia, unless massive subsidization of the white birth rate is undertaken.
America's future is to be Latin America from the Arctic Ocean to Tierra del Fuego.
Demography is destiny, and the fecund do inherit the earth.
Even more relevant, perhaps, is the marital birthrate. And in the USA, it's way below replacement. American children --- of any race--- born in wedlock and raised by a stable, committed mother and father are the doers, the dreamers, the achievers, the builders of of our cities, our nation, our civilization.
Children born out of wedlock, or with fathers "missing in action," -- God bless them, God protect them, God help them! ---but they're far more likely to be alienated, sullen, predators and parasites, undereducated and unemployed, future converts to Islam and the burden of America's future.
This imperiled future is not something that was brought upon us by The Gay Agenda, or illegal immigrants, or Muslims. It's something we've brought upon our very selves.