As a Canadian, I fear the repercussions if Christian Nationalists should succeed in controlling the American government. We share the longest border with the states as well as having them as our biggest trading partner. It would be inevitable that Canada would be affected negatively.

He's wrong, Christianity started getting into politics in the 1950's when they put "In god we trust" on our currency.

"Jesus is my savior"?

"Trump is my president"?

There is no way that such mental defectives can be saved from their own stupidity.

A large group within Christian Nationalism is the Dominionists. Google it. It'll make your skin crawl.
Can you imagine what might happen if the Republicans lock up a permanent majority in the U.S. Congress? If the presidency is guaranteed to be in Republican hands? If vacancies at the U.S. Supreme Court are always filled by right-wing ideologues?
It could very easily happen, and soon. Republicans are rigging elections in most, of not all, states in which they are in the numerical majority. It will make it extremely difficult, if not impossible, for Democrats in those states to EVER be in power again, on the local, or state, or federal, level. If enough states fall into that category of permanent one-party rule, we could effectively become a hybrid between a theocracy and an oligarchy (The rich aren't going surrender THEIR influence, after all), a "theoligarchy," as it were. These Christian Nationalists will have a significant voice in such a permanent government. Perhaps, over time, a dominant one. Regardless, it will be a radically different country than the one we live in now.
If that doesn't scare the hell out of you, nothing will.

They are need to lose their tax exempt status