And just to throw fuel on the fire, I'm not just worried that the GOP will simply yawn and allow things to continue (to deteriorate) if Trump is charged, but that we are relying on one man to solve everything. We have formed this messiah like complex around Mueller. That he will swoop down, like a holy avenger, and lay out in such detail, in such a formidable locked up case, about Donald Trump's overwhelming guilt on various fronts. Money Laundering, bribery, using campaign funds illegally, and of course conspiracy with a foreign power to influence the election. To the point that the GOP will have no choice.
What if they get to Mueller too? What if he is 'convinced' to dampen down the charges? Comey was a 'good' Republican too. So he felt compelled to share the information that the FBI had some new emails, based on Weiner's wife's account. No actual proof of wrong doing, just that they had new info to look at. But he felt, as a Republican, that he'd not be fair, or not seen as fair with his peers in the party, if it was found out after (Hillary won) that he had not mentioned these emails.....especially if they ended up being relevant and damning. At least that was his excuse.
Party loyalty may make him pull back the reins to not tar and feather the whole party.....even if many more are guilty.
He could restrict his indictments to the circle around Trump, and conclude that there is not enough proof that Trump himself was aware of the collusion.
He may also be convinced by Trump-leaning military and intelligence brass that NOT indicting Trump is a matter of 'national security'.
Or he may even be subject to physical violence threats, if not to him then his family.
Many situations could happen besides the rainbows and unicorns we are all envisioning ie. Mueller.