Sessions WAS officially part of of 45's campaign (as advisor) starting in feb 2016.  And yeah, he lied, not prevaricate  but lied.  He could have saved himself a lot of trouble if he had just answered THE question Franken asked instead he did the typical political sleight of hand and pivoted to some nonsense about people saying he was a surrogate ..then he pulled the typical lawyer trick, which is to muddy the waters in his issued statement that he never met with russians to discuss campaign issues.

‘I’m not aware of any of those activities. I have been called a surrogate a time or two in that campaign and I did not have communications with the Russians.’

‘I’ve never met with any Russian officials to discuss issues of the campaign. I have no idea what this allegation is about. It is false".