Entering Tuesday's primaries, some national polls showed a dip for Donald Trump, while there was talk that Bernie Sanders' campaign was all but dead.
Never mind all that. Sanders had one of his most important victories of the Democratic race, winning his first primary in a state with a large (23 percent) black electorate and carrying a state where Hillary Clinton was the favorite.
Sanders still fell further behind Clinton in the delegate race on Tuesday night, because of the former secretary of state getting more than 80 percent of the vote in Mississippi. Clinton only narrowly lost Michigan, meaning she and Sanders will split the delegates.
The former secretary of state remains the heavy front-runner in the Democratic race.
Clinton won 81 delegates last night, compared to 64 for Sanders. She leads over 754 to 541 among pledged delegates, with 2,383 needed to win the nomination.
But with primaries in Florida, Illinois, Ohio, Missouri and North Carolina next week, Clinton's path to the Democratic nomination no longer looks completely assured.
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.
Cruz did win the majority of very conservative voters, according to exit polls. They were about half of Mississippi's electorate.
But like in previous primary contests, Cruz lagged way behind Trump in Mississippi among voters who identified themselves as moderate and somewhat conservative. The exit polls showed that about half of Mississippi's GOP electorate was either moderate or somewhat conservative, and Trump won by more than 25 percent over Cruz among those voters.
As the primaries move north next week, even fewer of the GOP voters will be very conservative, and this looms as a huge barrier for the Texas senator.
Kasich spent much of the last week campaigning extensively in Michigan and was surging in polls. But he was about even with Trump in the wealthy suburbs around Detroit and among Republicans with college degrees. He needed to win big margins in urban areas to make up for Trump's strength in more rural areas.
One of Kasich's problems in Michigan and potentially in other states is that many of the Republicans with college degrees who don't back Trump are very conservative and evangelical and therefore support Cruz.
With the college-educated vote divided three ways, Trump easily won Michigan because of his advantage among rural voters and those who don't have college degrees, the mogul's base.
Rubio finished below 10 percent in both states, continuing a string of dismal finishes. He is banking on winning the Florida primary next week, but Republican voters there could opt for other candidates if they sense Rubio is fading and view him as having no chance at the nomination.
At least in Michigan, Kasich won the kinds of voters (somewhat conservative, college graduates) who had backed Rubio in previous primaries.
Trump's wins were fairly narrow, and he did not make huge gains in terms of delegates. But the results showed the real estate mogul is not at all fading, despite lackluster showings in Saturday's primaries and some national polls that found growing resistance to him in the GOP.
The results in Michigan, where Mitt Romney's father was governor and Romney won 2008 and 2012 primaries, also suggest that the 2012 GOP nominee's sharp denunciation of Trump last week had limited impact on Republican voters.