America First really just means anti-Europe. These guys HATE Europe and I mean HATE. The MAGA folks are pro-authoritarian, pro-fascism, pro-Russia. The fault line is political. Europe is, in many ways, socialist. Elections are democratic but economic and social policies are socialist. Russia is a far-right dictatorship. This is what they want. I mean I think they realize we won't ever get THAT far but more like Orban's Hungary.
So what MAGA wants is a weakened Europe, a weakened Canada (socialist), a weakened Australia. They want a new world order along the lines of Russia, Hungary, etc. In fact, if there wasn't so much opposition against this, I am 100% positive that MAGA would rather align with Russia, Hungary, Belarus, maybe get Turkey in there. Europe is a threat to MAGA. And that's why they want to be "America First."