He won't be re-elected.
He only won because a small handful of moderates in swing states believed the Russian propaganda.
The repubs on their own are not enough to get a president elected. They need to swing moderates, and regardless of the Mueller report, moderates are not going to vote for him again. Dems on their own are enough to get anyone elected IF that candidate mobilizes the minority vote, like Obama 2008 and 2012.