A new Pew Research Center study indicates that the conversation on Twitter over current events doesn't always reflect the larger American public opinion. Actually, it's often well off the mark:
Although sentiment on Twitter can sometimes match that of the general population, it is not a reliable proxy for public opinion. During the 2012 presidential race, Republican candidate Ron Paul easily won the Twitter primary — 55% of the conversation about him was positive, with only 15% negative. Voters rendered a very different verdict. After the Newtown tragedy, 64% of the Twitter conversation supported stricter gun controls, while 21% opposed them. A Pew Research Center survey in the same period produced a far more mixed verdict, with 49% saying it is more important to control gun ownership and 42% saying it is more important to protect gun rights.