I have recently applied to a PhD program in religion, with a focus on gender and culture, and I used as my main selling point the fact that my upbringing gave me a front and center view of the way that religion was used both (1) to make people "American" and (2) to define and internalize gender norms, and (3) I have seen the way that religious constructions of "patriotism" and religious constructions of manliness go hand in hand. I think many people with an upbringing similar to mine have had that experience. But I have to admit, some times I'm surprised at how much norms similar to the ones under which I was raised have a reach that far surpasses the reach of the religion in which I was raised.
I shouldn't be surprised, because I'm one of those former fundamentalists who lost their religion and then became a libertarian, and I have seen the type of masculinity that gets idealized in this corner of the political spectrum. It's like the Baptist type of manliness, but with sin. Not that I wasn't sinning when I was a Baptist - I was probably sinning more - but there's a brashness in libertarian-leaning conservatism that relishes looking mean and horny.
According to Pew, Americans' views of gender became much more conservative in just the past few years. The proportion of respondents who said that a person's gender can be different from the sex that they were assigned at birth dropped from 44% in September 2017 to 38% in May 2022, and the proportion of respondents who said that a person's gender can only correspond to the sex that they were assigned at birth rose from 54% in September 2017 to 60% in May 2022.
As of 2014 only 25.4% of Americans were evangelical, my guess is that Americans did not suddenly start becoming evangelical or fundamentalist in these rates. But, also according to Pew, evangelical Christianity gained a net 4% increase in adherents among White Americans during the Trump years, between 2016 and 2020.
To me it looks like religion is a main player, but not the only player. I think it's also important to point out that religious-like dynamics can be involved with religious belief-like norms in spaces where there is no formal religious structure present - for instance, the way my generation seems to pursue meaning through politics and astrology.
But I think a deeper thing going on is a flight to a type of manliness where the idealized man represents strength, security, and safety. In my view this is happening left of center just as much as it's happening on the right, and you see it not just in President Biden's vintage blue collar mannerisms but also in a younger political candidate's campaign video showing himself as a law enforcement agent against sex trafficking, as well as a loving father of White baby girls at home. This desire for man the protector will be catered to by any venue that offers meaning, be they religious, political, or even economic.