Overview:
Yes, the United States is a representative republic (or constitutional republic), where citizens elect officials to make decisions on their behalf rather than voting directly on laws. It is also accurately described as a federal representative democracy, combining elements of direct representation and constitutional constraints on power.
Does that satisfy you?
Not at all. A Constitutional Republic chains legislatures down.
A representative republic has no chains on representatives and they can pass any damn thing they want.
You and AI can't figure that out?
They are NOT the same thing.