He was asked about meeting with Russians in regards to the campaign, which he answered truthfully.
The Democrats, being the shitbags they are, took his answer, spun it, distorted it, and make a big hoopla out of it.
From a questionnaire:
Sen. Patrick Leahy, D-Vt., asked: "Several of the President-elect’s nominees or senior advisers have Russian ties. Have you been in contact with anyone connected to any part of the Russian government about the 2016 election, either before or after election day?"
Sessions responded, in total: "No."