King Charles has about as much influence on the world as my mom does. Less, perhaps - my mom has a lot of friends. In the US, we mostly need to worry about the unelected bureaucracies (EPA, FDA, USDA, CIA, FBI, etc.) under the Executive branch imposing decisions furthering the Leftist agenda on the rest of us. This happens regardless of whether the POTUS is a Democrat or Republican.
The Royals have a lot of money—all of it is used for evil purposes these days.