It seems to me we are mixing apples and fruit flies. For example, events like this happen on a recurring basis in this country.
http://www.politico.com/news/stories/0609/23454.html And they certainly weren't gathering to cheer the results of the latest election!
Not to mention the daily spleen venting on Limbaugh, Fox, etc. The suggestion that the U.S. doesn't tolerate dissent is horrendously simplistic.
Even the Bush administration didn't do a great deal to stop opposition gatherings so much as they tried to keep the dissenters out of theirs.
The parallels are superficial at best.