Both Democratic candidates Hillary Clinton and Bernie Sanders spoke passionately about the desire to stop deporting immigrants who entered the country illegally and to provide a path to citizenship at The Washington Post/Univision debate in Miami. (Sarah Parnass/The Washington Post)

Democrats got a taste Wednesday night of where their nominating contest between Hillary Clinton and Bernie Sanders could be heading — toward a grueling and increasingly contentious battle that could continue until the primaries end in June.

A few days ago, Wednesday’s debate here appeared as if it might be an anticlimax as Clinton rolled toward the nomination. Instead, Sanders arrived reenergized and reinvigorated after his surprising victory in Michigan. Rather than questions about Sanders’s viability, Clinton faced questions about what had gone wrong with her campaign.

The two squabbled at length over immigration. They traded charges over bailing out the automobile industry. They argued again over health care and about how to combat climate change. A quiet start turned into a spirited and at times tense series of exchanges that highlighted their differences and the state of their competition.

Clinton sought to brush aside her Michigan loss, pointing to a big victory in Mississippi and the fact that she emerged with more total delegates on Tuesday than her opponent. But it was clear that, if she remains the front-runner for the nomination, she has yet to put to rest questions about her candidacy or put away an opponent who has proved to be more resilient and effective than most people imagined.

Wednesday’s debate settled little. Both Clinton and Sanders were effective in making their cases. Picking winners and losers seemed beside the point. From here on, the voters will decide winners and losers, week after week, in primaries and caucuses. Clinton may hold a lead in pledged delegates, but that isn’t likely to intimidate Sanders after what happened in Michigan.

At a debate hosted by The Washington Post and Univision in Miami, a Guatemalan woman whose husband was deported asked candidates Bernie Sanders and Hillary Clinton what they would do reunite families. Lucia Quiej brought her five children, who haven't seen their father in three years, to the debate. (The Washington Post)

Clinton should be familiar with what awaits her in the weeks ahead. She went through this in 2008 against then-Sen. Barack Obama, but from the other side, playing the role that Sanders plays today: the dogged challenger hanging in against long odds.

Eight years ago, Obama was on the brink of ending the race for the nomination, having won 11 consecutive victories in February after Super Tuesday. One last obstacle remained: contests in Ohio and Texas in early March.

Then, Bill Clinton set his wife’s expectations almost impossibly high. He suggested that a loss in either state would knock her out of the race. The Obama team poured more than $15 million into those contests, determined to bring the race to a close.

Instead, Clinton began to find her voice — with a more populist economic message. Sound familiar? She went on to win Ohio and a popular-vote victory in the Texas primary. A dejected Obama knew instantly what the results meant. Though he had a lead in delegates that would be difficult to surmount, he realized the race would grind on interminably for three more months.

That’s the possible impact of what happened in Michigan on Tuesday. A Clinton victory could have effectively ended Sanders’s rationale for continuing, though it was doubtful he would have gotten out of the race soon. Now, though he trails in pledged delegates by a substantial margin, he has been revived, just as Clinton was eight years ago this month. This cannot be a happy moment for Clinton this week as she assesses the cost of her Michigan loss.

Sanders had been told just before Tuesday’s vote that he probably would lose narrowly. Clinton’s campaign knew it was possible, though not necessarily likely, that she could lose Michigan. The demographics played better to Sanders than other recent states. Ironically it was her ability to win white, working-class Democrats against Obama that kept her 2008 campaign going. Against Sanders on Tuesday, she lost not only whites without college degrees but also whites with college degrees.

Much of this goes to the issue of the continuing weakness in her candidacy, the issues of trust and authenticity. Asked a direct question about this in the debate, Clinton said, “I do take responsibility.” She followed that by saying, “I am not a natural politician, in case you haven’t noticed, unlike my husband and President Obama . . . I have to do the best I can.”

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After a year of campaigning, Clinton still seems not to have found a comfortable voice or a message that comes from her heart, unlike eight years ago as she battled to overtake Obama. This came to the fore in Michigan, a trade-sensitive state, where she struggled to demonstrate that she is as resistant to trade agreements as her opponent.

Her attack on Sanders in last Sunday’s debate as an opponent of the auto bailout was a stretch at best, a deliberate distortion at worst. On Tuesday she doubled down on the issue, seeking to show that Sanders had opposed a bill early in 2009 that included funds to save the industry.

But almost immediately after she did, David Axelrod, who was senior adviser to Obama in the White House, tweeted this: “She did it again and I’ll say it again. It’s misleading to imply that TARP II was an auto bailout bill.”

The tactic was reminiscent of the campaign’s earlier claim that Sanders wanted to dismantle the Affordable Care Act and leave millions of people without health insurance — an argument that, no matter how one feels about his support for a single-payer type system, did not ring true. Sanders’s message has defined the contest and she has had to respond to it, just as she has had to adapt to a changing Democratic Party.

Clinton’s clear advantage today is the same one Obama enjoyed in 2008 after he lost Ohio and Texas. Thanks to Democratic rules of proportionality, Sanders probably will struggle to make up his deficit in delegates. That hill is even higher when Clinton’s support from elected officials and party leaders — the superdelegates — is included.

Next week will bring contests in Florida, Ohio, Illinois, Missouri and North Carolina. Florida and North Carolina look good for Clinton; the other three present opportunities for Sanders, though none will be easy for him. By next week at this time, if she runs the table or comes close, the conversation might have shifted again, to the reality of the delegate math.

That, however, will not deter Sanders. He sees the calendar farther ahead as increasingly favorable. He has the money and now the incentive to stay in until the end and already is eyeing big efforts in big states such as New York and California. His advisers believe he can win a series of states later in March and beyond, even if he makes much less progress in cutting down Clinton’s advantage in delegates.

Whatever transpires from here, this is not the campaign Clinton envisioned. She remains the favorite to win the nomination. Michigan did not change that. But because of that vote, she faces renewed doubts about her effectiveness as a candidate. They are many of the same ones she has been dealing with since the campaign began long ago.