By Marcus Leach

US President, Barack Obama, launched his bid for a second term in the White House on Monday through the medium of email and a video release.

Having admitted he had fallen short of delivering the promises that saw him win a historic election back in 2008, he has asked his supports to begin assembling a grassroots army for the 2012 campaign.

"We've always known that lasting change wouldn't come quickly or easily. It never does," Obama said in the email, which came in tandem with a short video, utilising social media in today's society.

The video was short and to the point, asking people to maintain their faith in him as he looks to build on his first term in the White House.

"Americans have had lots of time now to see Obama perform as president, warts and all," says Boston University political scientist Thomas Whalen. "His job now is to convince voters that the best times are in front of them - that you haven't seen anything yet."