Rush Limbaugh started broadcasting in the 80's. Fox News in the 90's. Prior to that you had decades of propaganda against "communists" and anti-war protesters. Prior to that you had blatant lies about what would happen if black people got civil rights. Before that you had blatant lies about women's suffrage. The bullshit has always existed in very large quantities. The common uniting thread for the vast majority of the bullshit is conservative beliefs. They are always doing their most to make the world a worse place for some group or another.