I say strident left because some people can still be reached. Pew in 2017 did the best decomposition I've seen.
The Solid Liberals (Antifa snowflakes) and Devout and Diverse Dems (muscle/rioters) are basically lost causes. Those are ones who've made politics their religion. The other two groups aren't enamored with their Dem brethren. While they may not love Trump, they like a leader who tries to bring jobs back to America, who isn't a shrinking violet internationally, and doesn't get pushed around doesnt get pushed around domestically.
It is these latter two groups where Trump is making a play. He doesn't need the political religionists...he's simply being himself and saying "what have you got to loose?" If he can pick off 20-30% of that group without too many squishy RINOs bolting, he's going to do well.
In fact, if you think about it, the article has it backwards: The Political Religionists Are Helping Drive Normals Away From The Democrat Party.