level of a criminal offense.
http://www.nationalreview.com/article/453264/donald-trump-george-papadopoulos-indictment-exculpatory-trump
As observed above, this brings us back to the meaning of “collusion.” I’ve long argued that this term has been used by Trump’s accusers because they don’t have proof of criminal collusion. The term “collusion” can have a dark connotation, but it really only means some kind of concerted activity — not necessarily illegal. Prosecutors don’t care about collusion; they care about conspiracy — an agreement by two or more people to commit a violation of a criminal statute. That is, even if there is some concerted activity, collusion is not a crime unless the Trump campaign conspired with the Putin regime to do something federal law makes a crime — for example, to hack communications systems. If Trump officials and associates did not do this, then their activities may be unsavory, but they are not criminal. It is a disgraceful thing for an American political candidate to seek damaging information about his or her opponent from a despicable, anti-American regime. But it is not illegal. A criminal investigation is about proving crimes, not revealing dirty politics.