With almost all votes counted, Clinton bagged a massive 73.5 per cent votes as against just 23 per cent by Sanders. The victory is her strongest yet in the 2016 primary contest after she narrowly won the Iowa caucuses and was trounced by Bernie Sanders in the New Hampshire primary.
Clinton won the Nevada caucuses decisively earlier this week by five percentage points. Today's win gives Clinton, 68, a decisive advantage ahead of the "Super Tuesday", when the Democratic Party's primary would be held in all states.
The massive support that she received from black voters could carry over to other states next week including Alabama, Texas and Georgia, political pundits believed. According to an MSNBC exit poll, Clinton won 87 per cent of the black votes.
And in a pointed dig at Republican nominee Donald Trump, she said: "Despite what you hear, we don't need to 'make America great again'. America has never stopped being great. But we do need to make America whole again."
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Trump, 69, was quick to shot back. At an impressive rally in Millington, the real estate tycoon referred to her email controversy and alleged that the FBI was trying to give her a clean chit. But he did acknowledge that Clinton is most likely to be the Democratic party's presidential nominee.
Sanders, who conceded defeat within two hours of polls opening when he flew out of the state to Texas and Minnesota - two of the Super Tuesday battlegrounds, congratulated Clinton on her victory, but said the real campaign has just begun.
"In just three days, Democrats in 11 states will pick 10 times more pledged delegates on one day than were selected in the four early states so far in this campaign. Our grassroots political revolution is growing state by state, and we won't stop now," the 74-year-old Vermont Senator said.
"When we come together, and don't let people like Donald Trump try to divide us, we can create an economy that works for all of us and not just the top 1 percent," he said.