Are democrats capable of proving that the election was not stolen?
Accepting a fraudulent result and moving on from the 2020 election does not mean that it wasn’t stolen.
That is, of course, a logical impossibility.
The burden of proof is on those who claim that the election was fraudulent/stolen/dishonest/whatever. The problem with such proof has always been that no court will allow them to present it. This problem is MUCH older than 2020.