Affiliation has very little impact on America's general religious behavior or culture. People that just affiliated but only went to church maybe once a year moved to more comfortable to say non-religious?
Church attendance for Protestant Churches is at an all time high. Protestant political power is at an all time high in America.
Trumpism has made the Protestant church morally bankrupt but that hasn't nor will it change the next generation of intrinsically religious people.
This plays into the Protestant/Evangelical narrative of being persecuted and dying breed. They love saying negative its the end of God in America in 20 years since the 70s. Even int he midst of the greatest religious explosion in American History. Just look up George Barna, that guy is a millionaire for twisting the statistics to make religion look like it is dying his whole life. He is the lied a ton and people still listen to him because they love gloom and doom.