Intersindical is a leftist organization which was formed as a result of the 2002 election of President Lula. Although Lula was originally a leftist too, many critics are concerned with the right (neo-liberal) turn he has taken with regard to economic and political policies in Brasil. Hence the emergence of a new group of leftist organizations, of which Intersindical is one. Also in this new cohort of political action against the present government is the PSOL (Party Socialism and Liberty) and the PCB (Partido Comunista Brasileiro or the Brasilian Communist Party). The PCB was initially established in Brasil in 1922, shortly after the 1917 Revolution in Russia. And, although it has undergone extensive revision in the past 75 years, it is still adherent to Marxist-Leninist ideology. This may explain the hammer and sickle on the flag below. Overall, these groups are comprised of "workers, landless activists and youth from all over the country" who are increasingly dissatisfied with Lula Administration policies, according to a SocialistWorld.net article from July 2008.
The crowds were small and fairly sanguine as they marched through the main thorough fares of Campinas. Indeed there was an absence of militancy or aggression amongst the protesters but they were protesters of a type never seen on the streets of American cities. After all, when was the last time you saw the Communists marching in broad daylight in Sacramento?
In conclusion, if this were the only measure by which a society were judged, then I would say that Brasil's democracy is healthier than the United States' simply by virtue of the political protests on display.