Alexandre Auguste Ledru-Rollin, as quoted (whether justly or not) by Eugène de Mirecourt, Ledru Rollin, Les contemporaines/Collection "Contemporaines" 84 (Paris: Gustave Havard, 1857), 11. This has been attributed to others, but Ledru-Rollin (1807-1874) is the one cited by the 8th edition of the Oxford dictionary of quotations. Diogenes Allen used something very like this a lot, though I did not think back then to trace it to source.
Mirecourt prefaces this with the following:
The destiny of this man must necessarily end in ridicule.
One day, the popular tide traverses the street, and the great leader gives way to the first brawlers who acclaim him.
They sweep him along. They cast him into the hornet’s nest of a Convention [in order] to make fun [of him], and this frustrated dictator consoles himself with this remark, which paints him from toe to head: