After registering his win against Mitt Romney in the re-election presidential polls, Barack Obama thanked his supporters for making his White House comeback possible once again. "This happened because of you. Thank you," Obama tweeted. Obama has become the second Democrat to win a second four-year White House term since World War II. Meanwhile, hundreds of people gathered outside White House to celebrate the victory. People took to the streets, climbed trees and waved American flags after the projections that Obama beat Republican challenger Mitt Romney at the end of a long and bitter campaign.