Updating with Gov. Brian Kemp’s response:
The 2020 election in Georgia was not stolen.
For nearly three years now, anyone with evidence of fraud has failed to come forward - under oath - and prove anything in a court of law. Our elections in Georgia are secure, accessible, and fair and will continue to be as long as I am governor.
The future of our country is at stake in 2024 and that must be our focus.
Ehhh, just to be that guy, it is quite possible to prove a negative in certain circumstances. One of those is by exhaustive search, another is by proving a positive which is incompatible with the negative claim. I can prove the statement, “Sarah Silverman is not waiting in my bed for me right now,” fairly trivially by a quick check under the covers. One could also prove it by showing that she is actually somewhere else. A less-trivial example is the statement, “The election was not stolen by widespread voter fraud in 2020,” which has been proved by the efforts of countless election officials who have done both, ruling out the possibility of significant fraud anywhere, and positively proving the vote through multiple, routine election-integrity measures.
If you scope it all the way down to something miniscule then yes, but it’s not possible to prove negatives more generally.
Proving non-existence of a divine entity for instance.