Remember, there only around 3.8 people in Lebanon; see the CIA factbook: http://www.cia.gov/cia/publications/factbook/geos/le.html
So taking some of these figures of the turnout today, and assuming there's 300 million people in America, imagine if we had a turnout of similar proportions in a demonstration:
500,000 = 39 million.
800,000 = 63 million.
1.3 million = 103 million.
Yes, it's a very powerful statement. Will it impress Hezbollah? Probably not. Hezbollah's got all the guns.