Got fewer than 50 followers on Twitter? You probably support Obama

When it comes to preferences in the 2012 presidential campaign, Twitter follows a familiar political narrative. The Democrat, Barack Obama, draws his support from large numbers of people with limited influence, while the Republican, Mitt Romney, relies on tweets from a smaller, more powerful set of people.

And by power, of course, we mean one's number of Twitter followers.

A Yahoo News analysis of 80,000 political tweets from Wednesday, Aug. 1, determined that 62 percent of the tweets that expressed an opinion about Obama were positive. By contrast, only 39 percent of the tweets that took a position on Romney were positive.

This itself is not surprising, given demographic assumptions about the tweeting class. Twitter's new political index, which it unveiled Wednesday, found a similar differential in tweet support for the two candidates.

We divided the data by the number of followers each Twitter user in the sample has, to better tease out the dynamics of political expression on the service. The data was provided by Attensity, a company that specializes in analyzing social media on a large scale.

Obama, we found, draws his greatest support from people with 50 followers or fewer, whose tweets garner the president a favorability rating over 70 percent. But his support declines from there until you reach Twitter users with at least 10,000 followers—when his tweet favorability rating begins to rise again. (There aren't enough users with 25,000 followers or more to determine which candidate wins the tweets of the 1 percent.)

Romney, by contrast, draws a favorability rating below 40 percent from tweets issued by people with fewer than 500 followers. Then his tweet ratings start to rise, and he almost catches Obama among tweets from users with 2,500 to 4,900 followers. But once you hit power users with at least 5,000 followers, Romney's support starts to fall once more.

This type of distribution of support is common in politics. If you replace "Twitter followers" with "income," you see a similar picture of party preference.

In 2008, Obama won his greatest support with those in the lowest income ranges, exit poll data shows, while John McCain fared better among voters who made between $100,000 and $200,000.

But Obama began edging out McCain again once income levels reached $200,000—just as his Twitter approval stops falling among the 10,000-followers-and-up crowd at the end of the spectrum.

Like most things in politics, Twitter sentiment follows the money.