You could condescend to them, but then you'd be acting condescending to 100% of the people in your life. Everyone believes stupid shit, everywhere (and I mean everywhere). This fun feature came with our material conditions. You can instead adopt the socratic method, ask more (and this usually involves also challenging the premise rather than just the assertion), which should hopefully get them to stop saying stupid shit as soon as they hit their first contradictory snag. If they're stubborn and don't feel apologetic or confused, then pick your battle, you obviously won't make a communist right then and there. If you'll see this person long-term, and they still vaguely engage with you on politics despite you exposing a contradiction, then you can help steer them into a socratic dialogue by prodding more. Some of my friends (who admittedly engage with my infodumping, so ymmv) are quite "apolitical" but still engage with me even though I like to focus on the semantics of their statements (not sure if this is the right word), which help orient their thinking. If you overdo it then it might come off combative.