Sanders pips Clinton in Michigan, Trump marches on

Bernie Sanders breathed new life into his long-shot White House bid with a crucial win in Michigan's primary on Tuesday night, chipping away at Hillary Clinton's dominance in the Democratic presidential race.

Republican Donald Trump swept to victory in both Michigan and Mississippi, overcoming fierce efforts to blunt his momentum.

Even with Sanders' win, 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. Trump, too, fattened his lead over Texas Sen Ted Cruz, his closest rival.

 The front-runners turned their sights on November as they revelled in their victories.

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

In a nod toward the kind of traditional politics he's shunned, Trump emphasized the importance of helping Republican senators and House members get elected in November. Having entered Tuesday's contests facing a barrage of criticism from rival candidates and outside groups, he also delighted in overcoming the attacks.

 "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.

Sanders, meanwhile, said Michigan signalled that his campaign "is strong in every part of the country, and frankly we believe our strongest areas are yet to happen".

While a handful of recent losses to Cruz have raised questions about Trump's durability, Tuesday's contests marked another lost opportunity for rivals to slow his momentum. Next week's winner-take-all primaries in Ohio and Florida loom especially large as perhaps the last chance to stop Trump short.

Ohio governor John Kasich was in a fight for second place in Michigan and hoping a good showing would give him a boost heading into next week's crucial contest in his home state. Florida Sen Marco Rubio, a favourite of Republican elected officials, continued to struggle on Tuesday, upping the stakes for him at home on 15 March.

Two-horse race looms

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

During a campaign stop at a North Carolina church Tuesday, Cruz took on Trump for asking rally attendees to raise their hands and pledge their allegiance to him. He said the move strikes him as "profoundly wrong" and is something "kings and queens demand" of their subjects.

"I'm not here asking any of you to pledge your support of me," Cruz said, to thunderous applause and cheers. "I'm pledging my support of you."

Republicans were also holding contests Tuesday in Hawaii and Idaho. Republican candidates were fighting for 150 delegates, while 179 Democratic delegates were at stake in the party's two primaries. The delegates will select each party's presidential nominee at national conventions in July.

The economy ranked high on the list of concerns for voters heading to the polls in Michigan and Mississippi. At least 8 in 10 voters in each party's primary said they were worried about where the American economy is heading, according to early exit polls conducted 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, should be a good fit for him. But Clinton has led in polling.

The results in Mississippi underscored Clinton's overwhelming strength with black voters and Sanders' stunning inability to draw support from a constituency who are crucial to Democrats in the general election. Clinton carried nearly 9 in 10 black voters in Mississippi, mirroring her margins in other Southern states with large African-American populations.

After Tuesday's results, Clinton has accumulated 1,214 delegates and Sanders 566, including super delegates - 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 428 delegates, followed by Cruz with 315, Rubio with 151 and Kasich with 52. Winning the Republican nomination requires 1,237 delegates.