Listen
Former American vice-president Joe Biden now looks a certainty to win the race to challenge Donald Trump in November's presidential election.
Last month Biden was struggling to attract support but a huge win in South Carolina sparked a resurgence and a string of wins in Super Tuesday voting last week, and more wins yesterday.
His last remaining rival, Bernie Sanders, was counting on a big win in Michigan but blue collar working class voters threw their support behind Mr Biden.
The Vermont senator says he's staying in the race but he's under mounting pressure to step aside and give Biden a clear run.
Brent Budowsky from The Hill in Washington DC speaks to Susie Ferguson.
Read more here.