Amidst all the unknowns about this phase of the Mueller investigation, now that the "report" has been submitted, one thing we know from University of Texas/Texas Tribune Polling: reactions will be heavily determined by partisanship. Looking back over the time series of UT/TT Polls, attitudes towards Mueller, the Russia Investigation, and even the FBI as an organization split along partisan lines a considerable time ago.
Below are some of the most relevant attitudes from the February 2019 UT/TT poll: