Ah yes, they're exactly right. Jesus commanded the faithful to hire the government as a proxy for the purpose of stealing from others in the pursuit of a nebulous "social justice". /sarc
I invite the author of that screed to examine charitable contributions and volunteerism. You can summarize their argument as one big, long whine that evangelicals don't like using the government as an instrument of social engineering.
And as you hint in your last sentence, the person who wrote this is probably one of the first to wax poetic about the separation of Church and State. Yet in this instance, they seem irritated that White evangelicals don't use the state to enforce Biblical teachings.
Cognitive dissonance? Nope, because their only guiding principle is "by any means necessary". Taking contradictory positions is fine, as long as it's in service to that end.