LANSING, Mich. - Bernie Sanders breathed new life into his longshot White House bid with a crucial win in Michigan's primary, chipping away at Hillary Clinton's dominance in the Democratic presidential race. Republican Donald Trump swept to victory in Michigan, Mississippi and Hawaii, overcoming fierce efforts to blunt his momentum.

Even with Sanders' win Tuesday night, Clinton and Trump moved closer to a general election face-off. Clinton breezed to an easy victory in Mississippi, propelled by overwhelming support from black voters, and she now has more than half the delegates she needs to clinch the Democratic nomination at the party's national convention in July. Trump, too, padded his lead over Texas Sen. Ted Cruz.

Trump entered Tuesday's contests facing questions about his durability and ended the night with convincing victories in primaries in Mississippi and Michigan and in caucuses in Hawaii. Cruz added a win in Idaho, bolstering his case that he's the only candidate who can beat Trump with some regularity.

Florida Sen. Marco Rubio suffered another brutal drubbing, failing to pick up any delegates in Michigan and Mississippi. He faces a critical contest in Florida next week. Similarly, Ohio Gov. John Kasich desperately needs to win his home state next Tuesday to stay in the race.

Kasich finished third in Michigan, behind Trump and Cruz. It wasn't the boost he was looking for heading into next week's crucial contest in his home state.

With the prospect of a Trump nomination growing more likely, rival campaigns and outside groups have significantly stepped up efforts to discredit the real estate mogul. But the flood of attacks on Trump's business record and temperament have failed to slow his rise.

"Every single person who has attacked me has gone down," Trump said at one of his Florida resorts. He was flanked by tables packed with his branded retail products, including steaks, bottled water and wine, and defended his business record more thoroughly than he outlined his policy proposals for the country.

While a handful of recent losses to Cruz have raised questions about Trump's standing, Tuesday's contests marked another lost opportunity for rivals desperate to stop his march to the nomination. Next week's winner-take-all contests in Ohio and Florida loom as perhaps the last chance to block him short of a contested convention fight.

Rubio, whose appeal with party leaders hasn't been reciprocated by voters, insisted he would press on to Florida.

If Rubio and Kasich can't win in their home states, the Republican primary contest appears set to become a two-person race between Trump and Cruz. The Texas senator is sticking close in the delegate count, and with seven states in his win column he's argued he's the only candidate standing between the brash billionaire and the Republican nomination.

Some mainstream Republicans have cast both Trump and Cruz, an uncompromising conservative, as unelectable in a November face-off with the Democratic nominee. But they're quickly running out of options - and candidates -to prevent one of the men from becoming the Republican standard-bearer.

The economy ranked high on the list of concerns for voters in Michigan and Mississippi. At least 8 in 10 in each party's primary said they were worried about where the American economy is heading, according to exit polls conducted by Edison Research for The Associated Press and television networks.

Among Democrats, 8 in 10 voters in both states said the country's economic system benefits the wealthy, not all Americans.

Sanders has sought to tap into that concern, energizing young people and white, working-class voters with his calls for breaking up Wall Street banks and making tuition free at public colleges and universities. Michigan, with big college towns and a sizeable population of working-class voters, was a good fit for him, though his victory there was something of a surprise given that Clinton had led in polls heading into Tuesday's voting.

Still, Sanders has struggled mightily with black voters who are crucial to Democrats in the general election. In Mississippi, black voters comprised about two-thirds of the Democratic electorate and nearly 9 in 10 backed Clinton.

Clinton glossed over her contest with Sanders as she addressed supporters Tuesday night, choosing instead to focus her attention on Republicans and the general election.

"We are better than what we are being offered by the Republicans," she declared.

Sanders, a self-declared democratic socialist, said Michigan signalled "that we are a national campaign" after wins in different regions of the country.

"As more people get to know more about who we are and what our views are we're going to do very well," the Vermont senator said in a statement.

After Tuesday's results, Clinton has accumulated 1,214 delegates and Sanders 566, including superdelegates - members of Congress, governors and party officials who can support the candidate of their choice at the convention. Democrats need 2,383 delegates to win the nomination.

With Tuesday's wins, Trump leads the Republican field with 446 delegates, followed by Cruz with 347, Rubio with 151 and Kasich with 54. Winning the Republican nomination requires 1,237 delegates.