I know that Republicans will find nothing unusual here, but for the reality based amoungst us:
Forget about the suck up to his son... Start on the 2nd sentence.
"totally legal..." Buzz - wrong answer. It is illegal to work with foreign nationals, accept intelligence from foreign nationals or foreign countries for purposes of a domestic election.
"done all the time in politics.." Buzz - wrong answer. Opposition Research is done all the time, but not when provided by foreign nationals.
"This was a meeting to get information on an opponent..." Buzz - perjury. John-Boy Trump testified under oath to Congress that this meeting was about Russian adoptions, that took a bad turn. Perjury - you remember that Republicans, you found perjury to be impeachment worthy when President Clinton lied about oral sex.
"I did not know about it." That is where the rubber meets the road on collusion here. If he knew about it, then it was collusion. (PS Rudy Giuliani is correct in that "collusion" is not a crime. The actual crime -if his last line is a true as the prior one - is "Conspiracy to defraud the United States" - as in trying to rig the election with a foreign national and foreign government.