Want to run for President? You better start Tweeting.

It’s official: Spending a lot of time on social media sites is not just for fun anymore. In fact, it may be a prerequisite for holding one of the most serious jobs around: President of the United States.

A recent survey of adults found that a majority of respondents — 61 percent —  said they expect candidates in the 2012 U.S. presidential election to have a social media presence. And 38 percent of respondents in the survey, which polled adults on behalf of brand agency Digitas, said that information found on social media sites such as Twitter and Facebook will help determine their voting choices just as much as TV or newspapers.

Politicians could do well to pay attention to such opinions: According to Digitas, 82 percent of U.S. adults are social media users, and 88 percent of U.S. adults who are social media users are registered voters.

Not surprisingly, younger adults are more likely than other age groups to prioritize a candidate’s online presence over traditional media appearances. 51 percent of people aged 18 to 34 said that social networks will impact their voting choice as much as traditional media, compared to 38 percent of those aged 35-44. The amount of people who prize online activity over continues to decline as age goes up, but the fraction still stays pretty robust: 29 percent of people aged 45-54, and 23 percent of people over 55 years old.

It’s an interesting evolution from past elections. In 2004, Howard Dean made big headlines because his online fundraising was so unique. In the last Presidential election of 2008, Republican candidate John McCain was roundly critiqued for his supposed computer illiteracy (McCain’s campaign said that his reticence online was not for lack of interest, but because his war wounds made typing painful.) Generally, in the past a Presidential candidate’s social media participation has been mostly seen as an interesting perk. This upcoming election, though, it’s turning out to be a must-have.

In the 20th century, the emergence of televised debates famously changed the tone of presidential elections — John F. Kennedy’s telegenic appearance during a crucial debate in 1960 famously helped boost him over rival Richard Nixon. It looks like the 21st century’s successful politicians will have to hone their online personas just as much as their TV appeal.