I can't say for Chaldean Christians but at anyrate most of the Lebanese Christians I know are big GOP supporters, as one told me word for word: "I love Bush and I love Trump!". I'd have to imagine Assyrians think the same way.
Lebanese Christians have a distinct set of reasons for that.
(1) Most Lebanese-American Christians are for all intents and purposes not Lebanese at all anymore, being multiple generations removed from the country and often the product of out-marriage with white people. (Ex. NH Gov. Chris Sununu is Lebanese-American: does anyone question him being anything other than a generic white guy?)
(2) For the more recent immigrants, the dynamics of Lebanese politics over the past 40 years or so lead them to favor the GOP for the same reason Cubans and Vietnamese have tended to: the US supported Christian-dominated political factions in the Lebanese civil war.
For Chaldeans, I could see location mattering. In Michigan, they might be more Republican-leaning due to vanity-of-tiny-differences issues with the Democratic-leaning Arab community. In California, that would probably be less of an issue.