In my understanding Christian nationals are a different group; kind of an idea that western nation are built for Christianity ( and white race) and immigrants and liberal values are destroying it as they are decreasing in numbers and people are leaving Christianity
Christian Evangelicals are a group ( around 1 in 4 in US) who think its necessary for Israel to be great again and stretch to boundaries it has in past ; before Jesus will arrive back and rapture will happen and take them in Sky before tribulation
These Evangelicals marry well with right wing Jewish community who also is waiting for their Messiah and for that its necessary to rebuilt the temple and need red Heifers for purification purposes for any one entering the temple
Evangelicals are helping those Jewish community members by raising them in Texas; but causing death and destruction along the way
wrote some thing along the lines