The point seems to be that Christian Nationalism doesn't really have much use for Christ. If one were to do a study involving asking those who self-identify with Christian Nationalism what they believe and think about Jesus, there would probably be a very diverse set of answers. Some might be theologically orthodox, others less so.
In my personal experience what I see and experience from the Christian Nationalist milieu is that Jesus just isn't really that important. Jesus functions primarily as a religious mascot rather than as Lord and Teacher. I don't think this is a novel feature of Christian Nationalism, this is--unfortunately--the result of turning Christianity into a civil religion in America. Christianity not as the religious body of teaching and practice that is based on Jesus Christ (Who He is, what He did, what He said) but is Christianity as civilization and cultural marker.
I've been coming up against that problem for the last twenty years. I was talking about this 20 years ago back when Beliefnet was around, and it's something I've been talking about here on Christian Forums for the last 15 years since I first joined. It shows up every time someone points God's commandments, especially Jesus' commandments, and perhaps even most especially in His Sermon on the Mount, and the general response is to not take it seriously. It happens every time when the point is made that Christ says that when He judges the nations He says to those on His right and on His left, "I was hungry" and "I was thirsty" but the response I get is, "That only applies to other Christians" or I'm told that we should prioritize certain groups of people. Why should I care about the stranger who is without food, I should instead only worry about if my kids are hungry.
It is in every attempt to remove Jesus as the ultimate authority of Christian life. To replace the Jesus we read about in Scripture with another Jesus. It's when someone like Mark Driscoll tried to say that Jesus was "A Dude" and that we can't have some wimpy sissy Jesus but some rugged manly man man Jesus. Rather than the Jesus of Mt. Calvary, the Jesus who weeps at the grave of His friend Lazarus, the Jesus who looks at the downtrodden and His heart breaks for them--He's replaced with a totally different fake Jesus. I'm told I can't believe in the Lamb because Jesus is "a lion now" or "will be a lion in the future"--but I don't know, my Bible says there is a Lamb slain from before the foundation of the world, that Lamb is seated at the right hand of God, worthy to open the scroll, and it is a Lamb who judges the world.