Senator Bernie Sanders
Senator Bernie SandersReuters

Senator Bernie Sanders on Thursday officially launched his populist, liberal campaign for the White House, savaging an American economic system that creates "immoral" and unsustainable disparities between rich and poor, according to AFP.

"We're in this race to win," the 73-year-old Sanders, an independent lawmaker who is little known outside political circles and his home state of Vermont, told reporters at a low-key, rushed announcement on the lawn outside the Capitol, where he has served in Congress since 1991.

By jumping into the presidential race, the self-described socialist Sanders presents a long-shot challenge to Democratic frontrunner Hillary Clinton but said he relishes the chance to go toe-to-toe with her in "serious debates over serious issues -- not political gossip."

For years Sanders has warned of the growing economic gap in America, stressing that "millionaires and billionaires" run a rigged system that benefits the wealthy at the expense of huge numbers of working-class and poor citizens.

"Ninety-nine percent of all new income generated in this country is going to the top one percent," he said Thursday.

"That type of economics is not only immoral, it's not only wrong, it is unsustainable," he added.

Sanders is vehemently opposed to recently implemented laws that relaxed campaign finance rules, which he said allows billionaire donors to buy candidates of their choosing.

He reiterated his fierce opposition to a massive trade pact under negotiation with Asia-Pacific nations, saying the deal would cost American jobs.

Sanders, whose father was a Jewish immigrant from Poland, was an eight-year mayor of Burlington, Vermont in the 1980s following a string of election losses for Congress and governor.

He eventually won a seat in Congress in 1990. He voted against authorizing the use of military force against Iraq in 1991 and again in 2002, when Clinton voted in support of the Iraq war resolution.

Sanders recently made headlines when he became the first senator to announce he would not be attending Prime Minister Binyamin Netanyahu’s speech before Congress.

“The president of the United States heads up our foreign policy. The idea that the president wasn’t even consulted — that is wrong and not a good thing for our country,” Sanders said at the time, referring to the fact that House of Representatives Speaker Republican John Boehner invited Netanyahu to make the speech without the knowledge of either the White House's or Democratic leaders in Congress.

“I’m not thinking about it. I’m not going. I may watch it on TV,” Sanders stressed.