The death of Eric Garner has struck a chord in a way that Michael Brown's did not. For one thing, there is video evidence lacking in the Michael Brown.
The outrage over the tactics used to arrest a man for selling untaxed cigarettes has provoked outrage. Further outrage ensued when a Grand Jury failed to indict, just as in the Michael Brown case. But there are some big differences in these two cases. Michael Brown credibly committed a crime against persons before his encounter with the police. Further, there is evidence that Brown put the life of officer Wilson in danger. From this video, we see that Garner was no such threat to the police.
We also have to ask why the police feel that they have to enforce tax policy? Even if Garner was in fact selling smokes illegally, why can't you give him a ticket and a fine? Why the arrest? What the hell is going on that the police have literally become the health police in New York.
The answer is that this the ultimate enforcement power of government. We should be careful about what we make illegal, because government has the force of arms to kill us to comply. This is why the individual mandate in Obamacare is so pernicious. I can easily imagine a scenario where someone dies as federal agents attempt to seize assets for non-payment of the health care penalty. Gives new meaning to the term "Death Panels."