Trump has every right to speak to other world leaders. He also has the right to ask another country to look into corruption if there is strong evidence that there is (which it’s very strong). So what if Biden is a political foe. If Joe didn’t do anything wrong (when he did because he even admitted it in video with his own words) then he’d have nothing to worry about. There’s a difference in letting someone that has done something wrong and brings a situation to the front that now needs to be investigated vs a group pointing the finger at someone and while pointing looking for anything they can for validity, even if it’s made up.