Former vice-president Joe Biden has cemented his position as front-runner in the Democratic race to take on President Donald Trump in November’s White House election.
Biden won Michigan – the biggest prize of primary voting on Tuesday – extending his lead over main rival Senator Bernie Sanders.
Five other states – Washington, Missouri, Mississippi, Idaho and North Dakota – voted on Tuesday.
Mr Biden also swept aside Mr Sanders in Missouri, Mississippi and Idaho.
As things stand, it is unclear if Mr Sanders would fight on until the party convention in July.
The Democrats’ next big election milestone is in a week’s time when 577 delegates are up for grabs.
To secure the nomination, a candidate needs the support of 1,991 delegates. Before Tuesday’s vote, Mr Biden had 648 to Mr Sanders’ 563.
The former vice-president had lagged behind his Democratic rivals in early voting states, but rebounded after big wins on Super Tuesday and endorsements from several former nomination rivals.
Thanking supporters from Philadelphia on Tuesday evening, Mr Biden said Democrats, including supporters of Bernie Sanders, could beat Donald Trump.
“It’s more than a comeback, this campaign,” he said. “It’s comeback for the soul of this nation.”
“Tonight we are a step closer to restoring dignity and honour to the White House,” Mr Biden added.
“We have to lead the world again,” the former vice-president said. “Donald Trump’s America First policy has made America alone.”