I see this used by supporters of President Bolsonaro, e.g. on Twitter as #fechadoscombolsonaro.
I know fechado means closed - is this some kind of pun on the idea of places being closed due to Covid-19 lockdowns?
Does fechados have a sense meaning “to be close [to someone’s way of thinking]”. The way I see it used is almost like “I stand with Bolsonaro”. I have not found any dictionary listing this sense but that’s my impression of how it is being used.