[JimRed]

You know how I know the Mueller has nothing? Cause he is going to announce it AFTER the election If he had the goods, it would have leaked by now or announced by now.

So the hope of the left is that since it went on so long, some or even many voters will think that there was some misbehavior, and vote accordingly. Or they fear announcing "We got nothing" will trigger a red wave in retaliation for the needless and drawn out investigation.

[JimRed]

Oh, forgot another possibility: they have something questionable but not proven, and are waiting to release it too close to the election for it to be countered or disproven.