Exit polls suggested that, unlike in other states, including Mississippi, black voters did not overwhelming reject Sanders. He appears to have won at least 30 percent of the black vote in Michigan, after getting less than 20 in several Southern states. Clinton won heavily-black Wayne County around Detroit, but with a more narrow margin than she has in other regions during the primary season that have lots of African-Americans.
And in the rest of Michigan, particularly its more rural areas, Sanders carried more than 60 percent of the vote in many counties. His performance in Michigan suggests Sanders could win rural counties in Ohio, Illinois, Florida and Missouri next week, a potential path to victory in those states if he does not overwhelmingly lose the black vote.
Trump's wins were significant not only because he extended his delegate lead but that his potential rivals illustrated fundamental weaknesses.
Texas Sen. Ted Cruz has been saying that he could win a one-on-one race with Trump. But he lost in Mississippi, a state that should have been favorable to Cruz, because it is in his home region, the South, and packed with very conservative voters and evangelicals, who tend to favor the senator.
Ohio Gov. John Kasich and Florida Sen. Marco Rubio barely campaigned in the state, so it was in effect a one-on-one between Trump and Cruz.