Keep in mind that later the DNC/MSM successfully impeached President Trump over what, a phone call, and later for telling a crowd to "peacefully and patriotically" protest the election results at the Capitol.
What do you think they would of done in the early days of Trump's administration to blockade both Sessions and Trump if Sessions had "interferred" with the Mueller Russian investigation? All we would have heard about would have been "obstruction of justice" charges and impeachment against two men who had campained on "we are a nation of laws" and "rule of law".
As it were, Trump appointed Session's own cheif of staff, Matt Whitaker, to be AAG while waiting on the Senate to approve Session's replacement, the Dems immediately took Whitaker to court to block him from taking control of the Mueller BS, that December the court sided with the WH, and Whitaker pulled the bogus version 2 of the scope memo Rosenstien had written which had given Mueller free reign to continue his witch hunt indefinately.
Mueller had to close shop, Rod Rosenstein no longer in charge, "decided" to retire. Goodbye Mr. Rosenstein, traitor. The Dems/MSM then had to scramble to their next political blockade.
Any attorney with half a brain would know that Sessions was conflicted due to his association with Trump, and that any potential defense of him would be a conflict. One of Trump’s faults - poor advisors.