Catholics are a minority denomination in America, and an especially small minority in the relevant states.
Russian Orthodoxy, on the other hand, encompasses ~95% of Russian Christians, and there is no organized alternative to it.
... Also, Trump 2024 won Catholics by 12 points (While 2020 and 2016 was a 50/50 split.)
Whatever the church's views are, unlike the evangelicals, it's not dictating to its members how they should vote.
The interesting part has more to do with the ideological fundation than with the electoral reality. It's not about winning a few percentage points, it's about the ground work for their political vision.
Like the Great Rus and Kirill give a cultural justification for Putin war and anchors them in an historical framework where they make sense, Trump (I mean Vance really) is using the evangelists and the threat of a perceived shift in what makes America America has a justification for his policies.
It's pervasive throughout Project 2025.