The rumor has it that Don Jr is in Mueller’s sights if that line is crossed Trump should just fire Mueller. Not a perfect solution since the rat states will take up the case but this has gone on long enough.
I've been convinced for months that these rumors are put out there by Democrats and RINO co-conspirators who realized a long time ago that goading Trump into firing Mueller is the only way to mount any credible campaign to remove him from office.