Yes, that’s generally what “believe the election was stolen” without further qualification means; its not a reference to the total sum of people who believe at least one election in the history of the US was stolen.
> For the previous one a majority of Democrats including high ranking Democrat politicians and officials were election deniers.
No, they weren’t.
https://fivethirtyeight.com/features/more-republicans-distru...
A large percentage of Democrats believe Russian interference and other improper interference influenced the election results, but that’s different than thinking the actual vote was rigged or invalid.