The leaks are not coming from Mueller. We all know this is the case, at least those of us tethered to reality anyway. The leaks all come AFTER Mueller and his team have met with someone to interview them, or they sit before a Grand Jury. Most of the leaks can trace back to people within the Trump administration itself, which leaks in an unprecedented fashion in modern American history.
And while it is true that the Democrats do not have anyone that stands out right now as the odds on favorite for the nomination, we can be all but assured that Trump will face a Primary challenger, or multiple challengers from within the GOP. He is likely also going to face a strong Independent conservative candidate, that will campaign from a position of returning sanity to the GOP and the right. With the ever-shrinking number of people registering as Republican, coupled with the massive number of people abandoning the party, Trump will be left with a ~30% base of voters that will not be capable of ensuring his victory. If he does not work to expand his base, rather than only focusing on them, he will be a one-term President. Bookmark it my friend.