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.