Christian Nationalism is a cynical, power-oriented distortion of Christianity that prioritizes political control, deception, or "ends justify the means" tactics over genuine faith - echoing Niccolò Machiavelli's ideas in The Prince about pragmatic ruthlessness, religion as a tool for social cohesion, and authoritarian appeals.
It is also good to remember that Christian Nationalism is just Roman Catholic Integralism with Protestant characteristics.
“The actual state of affairs may sometimes be so bad that a man is tempted to risk change even by revolutionary methods; to say that desperate diseases require desperate remedies and that necessity knows no law”
The fatal ideas of the Machiavellian prince
Other Worlds, CS Lewis