Joe Biden has opened up a 13-point lead over Bernie Sanders in a new national poll – the latest sign that the presidential race has dramatically swung his way since before Super Tuesday.

Biden leads Sanders 45 to 32 in a new Reuters / Ipsos poll released after he prevailed in 10 of 4 states on Super Tuesday and reshaped the race. Biden scored that performance after former rivals consolidated around his campaign end endorsed him.

Now, he and Sanders are preparing to battle in Midwest battlegrounds next week – in a clash that will determine whether they face a drawn-out slug-fest.

Less than two weeks ago, Sanders was holding an 11-point lead in the same survey.

Joe Biden has opened a commanding lead in a new national poll

There was more dramatic information out of Florida, where Sanders was already in trouble thanks to his comments defending aspects of the Fidel Castro regime in Cuba.

Biden was at 51.5 per cent in a new St. Pete Polls survey, with Sanders way back at 14 per cent. Billionaire Mike Bloomberg, who dropped out and endorsed Biden, was at 10.5 per cent. The poll was conducted online rather than through automated telephone contacts with Florida voters.

The presidential campaigns of Joe Biden and Bernie Sanders have each identified Michigan as their next critical battleground – with Biden hoping to take down Sanders in a state where he scored a critical win over Hillary Clinton in 2016.

The next big battle is brewing in Michigan, which is among six states that vote March 10. The state has suddenly emerged as the next critical race for the campaigns to try to make a statement, now that Biden has suddenly received frontrunner status.

Sanders has planned more of his signature rallies for the state, with events planned in Detroit and Grand Rapids in the coming days. Biden is planning his own Detroit rally for the day before the state's primary, plus a fundraiser. He also has scheduled an event in Ann Arbor, where he wants to mobilize University of Michigan students with a get-out-the-vote rally.

Biden and Bernie Sanders are taking their campaigns across the country

Sanders was thrown off balance after Biden won 10 of 14 states on Super Tuesday

Sen. Elizabeth Warren suspended her campaign Tuesday, but has yet to endorse

Biden is planning his own rally the day before the primary, plus a fundraiser.

Biden got a shot of momentum after his Super Tuesday victories, and has cleaned up in endorsements from his former rivals. On Wednesday he picked up the endorsements of Gov. Gretchen Whitmer and former Gov. Jennifer Granholm.

Michigan and Missouri are the biggest prizes on the electoral map on the 10th. The state also has symbolic power – it is one of a trio of traditionally Democratic stares where Donald Trump beat Hillary Clinton.

Michigan Gov. Gretchen Whitmer endorsed Biden on Thursday

Sanders scored a crucial win there in 2016 in what became his extended run against Hillary Clinton.

Biden, who ran up huge margins among African American voters in South Carolina and other southern states, wants to replicate his strategy. He also wants to make the state a proving ground for his case that he can take the fight to Trump over issues for working families.

Sanders is seeking reaffirmation for his own economic message, which on Wednesday included attacks on Biden for taking funds from billionaires and attacking his rival for backing the Wall Street bailout in 2008 and accusing him of favoring a 'dysfunctional and cruel' healthcare system.

A new Detroit News poll gives Biden a 7 point lead over Sanders, though the Vermont Senator led previously when an array of candidates were splitting the vote. Sen. Elizabeth Warren dropped out of the race Thursday after holding her Super Tuesday rally in Detroit.

'Michiganders have grit. We’re tough. We know what it’s like to be overlooked and counted out. And we know that when you get knocked down, you pick yourself up and get back to work. Joe Biden has been right there with us in the tough fights,' Whitmer said in endorsing Biden.