Barack Obama is on Twitter. So is Mitt Romney. And so are all the voters following the 2012 presidential contest, whether they know it or not.
The political world has flocked to Twitter, the social networking hub where information is shared through 140-character microbursts known as tweets.
While relatively few voters are on Twitter, it's become an essential tool for campaigns to test themes with a group of insiders who process and share those messages with the broader world.
So when a voter is exposed to any information related to the presidential contest, chances are it's been through the Twitter filter first.