What do you mean by Joe Sixpack?
In the United States, at least, the term "Joe Sixpack" is meant to refer to a working class man. He is supposed to be the epitome of what used to be the American public. He is a person who works in a blue collar job and who does not share in the cultural values of the elites of the country.
The term comes from the idea that such a person would like to drink beer. Beer (especially in previous decades) came mostly in packs of six in the US. This average person's liking for beer in six packs was supposed to show that he was a blue collar, "regular" American -- not someone who would be drinking white wine or martinis or something like that.
So, the term Joe Sixpack refers to a working class, blue collar American. It is often seen as a vision of what America used to be in the mid-to late 20th century. You will often see it used by people who wish America could return to that or who think that people like that are the "true" Americans.