Much of the Obama campaign was waged online
US civic engagement remains in the hands of the middle-class despite hopes that the internet would democratise political involvement.
Those are the findings of a report from the Pew Internet Project.
Online political engagement such as contacting officials, signing petitions and making donations is skewed towards richer and better educated Americans.
The report found signs that social networks could be encouraging younger people to get involved in politics.
According to the report 35% of US adults on incomes of at least $100,000 (£62,000) participate in two or more online political activities compared to just 8% of adults on incomes of less than $20,000 (£12,000).
However there are signs that social networks such as Twitter and Facebook could be changing that.
Some 31% of US citizens with a social network profile have engaged in either political or civic activities such as joining a political group or signing up as a friend of a particular candidate.
A further 15% of online adults had contributed to websites or blogs on a political or social issue.
"There are hints that forms of civic engagement anchored in blogs and social networking sites could alter long-standing patterns that are based on socioeconomic status," said the report.
The internet is widely believed to have played a huge part in the election of Barack Obama.
It was hoped that the digital campaign would spearhead more online activism and bring poorer Americans online.
The survey of 2,251 adults was conducted in August.