twitter's use in measurement, presidential debate sentiments

Presidential race in America has become a red hot topic in America (because they should care) and somewhat globally. After the first presidential debate between the republican Mitt Romney and the current president representing the democratic party, Barrack Obama, a lot of people seemed to think Romney won the debate according to a poll conducted by Gallup showed 72% of the people who watched the debate thought Romney won, an unprecedented approval rate. However the people of the twitterverse generally thought otherwise, with 61% of the messages related to the debate being in favour of Obama presented by the Pew Research Centre, though more of the tweets were about criticising Romney.

The entire debate lasts for around 90 minutes and could be a reason that not everyone will be watching the entirety of the debate and choose to follow updates or tweets from others for information relating to the debate. The question raised though is whether twitter can be an accurate gauge for where the sentiments of the the American population lie. For one, a lot of the tweets it may need to be interpreted between the lines, another reason is people can create an infinite amount of accounts theoretically, making it hard to conduct an accurate measure of the American's preferences.