NEW YORK — Republican Tim Pawlenty disclosed his 2012 presidential aspirations on Facebook. Rival Mitt Romney did it with a tweet. President Barack Obama kicked off his re-election bid with a digital video emailed to the 13 million online backers who helped power his historic campaign in 2008.

Welcome to The Social Network, presidential campaign edition.

The candidates and contenders have embraced the Internet to far greater degrees than previous White House campaigns, communicating directly with voters on platforms where they work and play. If Obama’s online army helped define the last campaign and Howard Dean’s Internet fundraising revolutionized the Democratic primary in 2004, next year’s race will be the first to reflect the broad cultural migration to the digital world.

“You have to take your message to the places where people are consuming content and spending their time,” said Romney’s online director, Zac Moffatt. “We have to recognize that people have choices and you have to reach them where they are, and on their terms.”

The most influential of those destinations include the video sharing website YouTube; Facebook, the giant social network with 500 million active users; and Twitter, the cacophonous conversational site where news is made and shared in tweets of 140 characters or less.

All the campaigns have a robust Facebook presence, using the site to post videos and messages and to host online discussions. In the latest indication of the site’s reach and influence, Obama plans to visit Facebook headquarters in California this coming Wednesday for a live chat with company founder Mark Zuckerberg and to take questions from users who submit questions on the site.

Candidates have embraced Twitter with an intensity that rivals pop star Justin Bieber’s. Twitter was the Republican hopefuls’ platform of choice last Wednesday, moments after Obama gave a budget speech calling for some tax increases and decrying GOP proposals to cut Medicare.

“President Obama doesn’t get it. The fear of higher taxes tomorrow hurts job creation today,” Mississippi Gov. Haley Barbour tweeted.

“The president’s plan will kill jobs and increase the deficit,” former House Speaker Newt Gingrich warned in a tweet, attaching a link to a more detailed statement posted on Facebook.

In the past, candidates would have pointed supporters to their websites for such a response. Now, as Moffatt puts it, “the campaign site may be headquarters, but it needs digital embassies across the web.“

Republicans once seemed slow to harness the power of the web. The party’s 2008 nominee, Arizona Sen. John McCain, told reporters he didn’t even use email. The 2012 hopefuls have worked hard to prove their Internet savvy, particularly with social media.

Pawlenty “understands the power of new technology and he wants it to be at the forefront. We are going to compete aggressively with President Obama in this space,“ spokesman Alex Conant said. Conant pointed to efforts to live stream videos to Facebook and award points and badges to supporters in a way that mirrors Foursquare, the emerging location-based mobile site.

Former Alaska Gov. Sarah Palin, McCain’s 2008 running mate and a potential presidential candidate this time, has made Facebook a centerpiece of her communication efforts to supporters.

Palin has been criticized for treating it as a one-way form of communication that allows her to bypass direct questions from reporters and voters. Other Republicans insist they’re willing to wade into the messy digital fray and cede some control of their message.

“We trust our supporters and want to err on the side of giving them more control, not less,” Conant said.

Just as social networking liberates candidates to take their message directly to voters, it offers plenty of pitfalls as well.

It’s prone to mischief, with dozens of fake Twitter accounts and Facebook pages popping up daily that are intended to embarrass the candidates. Also, a candidate’s gaffe or an inconsistency on issues can be counted on to go viral immediately.

Gingrich has gotten ensnared in some online traps. His apparent back-and-forth on whether the U.S. should intervene in the conflict in Libya was discussed widely and amplified online. He first advocated military engagement, then came out against it after Obama ordered airstrikes.

Twitter lit up with the news that a photo on Gingrich’s exploratory website showing people waving flags was a stock photo once used by the late liberal Sen. Ted Kennedy, D-Mass.

Spokesman Rick Tyler rejected such criticism and said Gingrich has pioneered the use of digital technology.

“Over 1.4 million people follow him on Twitter. He has a very active Facebook. There are eight websites connected to organizations started by Newt (that) use social media platforms to communicate to their coalitions,” Tyler said.

But Josh Dorner, who tracks GOP candidates online for the Center for American Progress, a liberal think tank, said the Republican presidential hopefuls appear to be unprepared for the unforgiving pace of the digital age.

Obama, who in 2008 had to recover from plenty of web-amplified flubs such as his comment that bitter small town voters “cling” to guns and religion, will probably be more nimble, Dorner said.

“We are moving in a warp speed environment, and none of the Republican candidates understand the media environment in which they’re operating. It puts them at a huge disadvantage to the president,” Dorner said.

Strategists also say the greatest digital innovation in 2012 may not even have surfaced yet, even as campaigns figure out how to do effective microtargeting ads for Facebook and work to develop “apps” for smart phones rather than laptops and traditional TV.

“As with anything, there’s going to be a shiny new cell phone every six months,” said Matt Ortega, a former online organizer for the Democratic National Committee. “You’re going to see both new tools and more sophistication in existing tools.”