I believe the article is important because of
1. The clarity with with the matter is laid out.
2. The empirical analysis of data most conservatives don't look at, or, unless they are academics, have access to.
3. The fact that it's in The Public Interest and written by two (probably liberal) professors of political science in the very liberal New York City University system.
It's a pity that the authors don't deal with either the origins of the term in 19th Century Germany, or the similar cultural struggle within Christianity in the US during the late 19th century between the mainline and what became known as fundamentalist worldviews. But, then, they are neither historians nor, one suspects, scholars of Protestantism.