To quote him ;
> I did not steal the crown. I found it lying in the gutter, and I picked it up with the sword. But it was the people who placed it on my head.
The man was massively popular with the populace [1] [2] and he got elected emperor with a referendum [3] to which 7 million people were called. By modern standard that barely qualifies, but for an emperor in 1804 ...
A common misconception was that the revolution was to remove the all powerful head of state. It wasn't, the people just wanted a competent one and improved living conditions.
[1] https://www.reddit.com/r/AskHistorians/comments/277eu3/why_i... [2] https://www.reddit.com/r/AskHistorians/comments/gli6nn/consi... [1] https://en.wikipedia.org/wiki/1804_French_constitutional_ref...
to be fair, the emperor climbed on the throne pretty much on his own; I think he had support across broad parts of the population, but it's not as if he was elected (and he didn't even start as an emperor, that came a few years after his coup)