Hillary Clinton enters a series of Super Tuesday contests poised to extend her lead over Democratic rival Bernie Sanders, who risks a major setback for his insurgent campaign with a poor showing in primaries and caucuses across the nation.

Backed by black voters, Clinton aimed for a sweep of Southern states holding primaries on Tuesday and polls showed her with a big advantage in Alabama, Arkansas, Georgia, Tennessee and Texas. Sanders could only bank on winning his home state of Vermont and both campaigns were vying for support in Colorado, Massachusetts, Minnesota, Oklahoma and Virginia.

"I am confident that if there is a large voter turnout today across this country we are going to do well," Sanders said after voting in his home state of Vermont. He joked, "After a lot of deliberation, I know that Bernie Sanders, here in Vermont, got at least one vote. I was working on my wife, so I probably got two."

All told, Clinton and Sanders were competing for 865 delegates in 11 states and American Samoa on Tuesday, the biggest single-day prize of the 2016 campaign. Black voters powered Clinton to victory in South Carolina last weekend, with 8 in 10 voting for her, and were expected to give her a huge advantage throughout the South.

Clinton starts Tuesday with 546 delegates, including super delegates — the party leaders and members of Congress who can support any candidate. Sanders has 87 delegates and needs to begin winning states with a healthy margin to gain ground on Clinton. It takes 2,383 delegates to win the nomination.

Speaking to journalists in Minneapolis Tuesday, Clinton declined to make any predictions, saying only that it was up to the voters to decide.

"Let’s see what voters decide in all these states that are lined up today and then we’ll take stock after it’s over," she said. "But I’m going to keep going. I’ve got a lot of work to do."

Clinton was making a quick jaunt into Minnesota and then joining with supporters in Miami, a destination that foreshadows the importance of Florida as a general election battleground. She has already turned her attention to Republican front-runner Donald Trump, arguing that she would be the best candidate to help Democrats hold onto the White House after President Barack Obama’s two terms.

"Obviously, he’s done very well," Clinton said Tuesday of Trump.

On the Republican race, Clinton said "It’s turned into a kind of one-upmanship on insulting and I don’t think that’s appropriate in a presidential campaign and I’m going to speak up on it. But I’m going to let them chose their nominee."

Sanders decamped to his home in Burlington, Vermont, where he planned to watch the returns with his home state’s faithful. At rallies in Minnesota and Massachusetts on Monday, Sanders vowed to fight on until the party’s convention in July and his advisers pointed to a calendar that would be more accommodating later this month.

Asked by reporters in Boston if he would hurt the party’s chances if he carried on, Sanders said only 15 states will have voted by Tuesday and it was "more than appropriate" to let people "vote for the candidate of their choice."

But the map, at least on Tuesday, did not appear to be helping Sanders. Because Democrats award their delegates proportionally, Clinton could use blowout victories in the South to add to her delegate haul.

Sanders was expected to win handily in Vermont but the other states where he was competing — Minnesota, Massachusetts and Oklahoma — were expected to be narrowly contested, making it unlikely he will cut into Clinton’s advantage.

Despite his obstacles, the Vermont senator has little incentive to fold. He reported raising more than $42 million in February, a sign that he will have the money to go deep into the spring. And his team views a series of caucuses in Nebraska and Kansas and Michigan’s primary later this month as places where he could regain some momentum.

Super Tuesday has been pivotal for the Clintons before. Then Arkansas Gov. Bill Clinton used a sweep of Southern states in March 1992 to establish himself as the front-runner for the party’s nomination, setting him on a course for the White House.

(Copyright (c) 2016 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

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