Could election violence come to the USA?

For many countries, including Jamaica, there is violence at election time. The past few weeks I while observing the US healthcare debate I wondered if we could see violence in the US in next years mid-term elections. Passions are high and there are screaming matches during townhalls , protests and rallys . In fact people are getting physical all over the country. One man in Miami was “clocked” in the face by another man who disagreed with his views on healthcare. The radio and TV talking heads are pumping people up. Could election violence come to the USA?