That's the great thing about life: Multiple things can be true at the same time.

Was the debate rigged? 100% it was. Over the last 20 years the left has turtled up from an intellectual point of view: they can't make actual points, they have no actual policies, they've been reduced to a quivering pile of name callers. Oh, they point to Trump and claim the new political discourse (where they openly root for violence and death) is a new thing but they've been having fantasies about doing in Republicans since Bush43. What we see today is just the natural evolution towards a place they've been marching to for decades.

As a part of the flaccid nature of their place in the intellectual food chain, to them, if there's NOT a thumb on the scale they just don't know how to function.

The other thing that is true is that Trump was highly stupid at that debate. He spent his valuable air time arguing over whether people left his rallies early or not and let his ego win. The disciplined Trump that ended Joe Biden's political career would have done the same for Kamala Harris had he just stuck to the issues....alas, a wasted opportunity. Looking at the polls it doesn't seem to have hurt him all that much.