The USA had a chance to repent, and it refused.
Many more than one. And the Christians of the USA have had many chances to rise up, but there's too much TeeVee to watch, too many ballgames to obsess over, too much trash to immerse in.
And yet millions of God-fearing Christians oppose this atrocity. Perhaps the end-time rapture theology is true. Why would God punish the righteous along with the wicked?