It's basically a good article. I have the first volume of Martin Marty's "Fundamentalism Project" which Marsden mentioned - it's called "Fundamentalisms Observed," and it makes it clear that there are extremists and loonies and "fundies" in all religious movements - Catholic, Jewish, Muslim, Hindus, Buddhists, Sikhs, Shintoists, etc. The human tendency to go to extremes on religious belief is by no means a monopoly of conservative Protestants.
Marsden seems to question the way Protestant fundamentalists have aligned themselves so closely with Trump. I voted for Trump, but personally I think it is unwise for us as fundies to identify too closely with him. I am concerned that if we make the upcoming November 2022 elections a referendum on allegiance to Trump, rather than on basic conservative principles, we may make it harder for conservative candidates to win.
Slight correction. In 2017, the Fundamental Baptist Fellowship International changed its name to Foundations Baptist Fellowship International, not Baptist Fellowship International as stated by Marsden. However, "Frontline," the official FBFI publication, still uses the old name Fundamental Baptist Fellowship International, which is a bit confusing.
Foundations Baptist Fellowship International | Contending for the Faith Once Delivered (fbfi.org)