Are you honestly that clueless about the law or are you being glib to cover Trump JR’s butt? Accepting aid in an election from a foreign government or national is against the law. And yes, that includes the secret exchange of dirt for opposition research. Furthermore, when going through the process of obtaining a government security clearance, you have to disclose any contact you’ve had with representatives of a foreign government or business. If it’s discovered that any members of the Trump Administration were directly or indirectly involved in the meetings, they’re in hot water itself.
Also in the legal world there’s this little thing called Mens Rea (“guilty mind”); if there is sufficient evidence that shows you were intending to commit a crime, then it doesn’t matter if you were actually successful in carrying it out. That’s the legal precedent sting operations are built on. Trump Jr received a email offering him to get into contact with a representative of the Russian government to obtain damaging information on the Clinton Campaign. He agreed to the meeting and went ahead and met with the attorney. At that point he showed clear intent to commit an illegal act regardless of whether he got any dirty laundry of Clinton or if he walked away empty handed.