NEW YORK --- Thursday's debate between Hillary Clinton and Bernie Sanders offered a revealing window into the current state of the Democratic campaign and a look at two candidates who have reached the limit of their patience with each other.
What started out many months ago as a relatively civil contest, in which both Sanders and Clinton seemed to resist negative attacks, has descended into the kind of competition that raises questions about how easily the party will come together once a winner has been crowned.
New York long has had a reputation for brawling politics, and the debate more than met that standard. Ahead of Tuesday's crucial primary, the two presidential candidates staged the most acrimonious forum of their increasingly nasty campaign.
From breaking up big banks to raising the minimum wage, from who is best equipped to run the country to who has a better position on restricting guns, from energy policy to U.S. policy in Libya and the Middle East, the two traded blows over and over and over.
Poking at Sanders, Clinton said, "I think you need to have the judgment on day one to be both president and commander in chief." To which Sanders responded moments later, "Do we really feel confident about a candidate saying that she's going to bring change in America when she is so dependent on big money interests?"
From there, the rancor only increased. Constantly interrupting one another, the onstage volume finally reached such a level that CNN's Wolf Blitzer warned, "If you're both screaming at each other, the viewers won't be able to hear either of you."
Sanders has been on a winning streak in recent weeks, but he arrived at Thursday's debate at the Brooklyn Navy Yard facing a potentially damaging defeat in next week's primary. His sense of urgency was palpable as he repeatedly attacked Clinton. She, in turn, fired back with the kind of disdain she has rarely shown.
It's questionable that many minds were changed by Thursday's debate. The tone and tenor suggested the degree to which both sides are now dug in for a contest that, despite Clinton's advantages in pledged delegates, will go all the way to the end of the primary season. The real question is how long it continues after that.
The debate opened with the issue that dominated the campaign last week - whether either believes the other is qualified to be president. Given the opportunity to de-escalate that confrontation, Sanders did the opposite, reprising his criticism with sharpness in his voice that drew cheers from his supporters in the audience.
As the question was posed to Sanders, Clinton turned 90 degrees to her left and eyed her opponent with a combination of skepticism and annoyance. And when he finished attacking her on Iraq and taking money from Wall Street and being supported by a super PAC, she tore into him as unable to answer fundamental questions about the core issues of his candidacy.
Those opening minutes set the tone for what was to come. For two candidates who claim still to respect each other, Clinton and Sanders displayed the opposite. They trod over familiar ground, issues that have been debated eight previous times during the campaign. But the gaps between them rarely seemed larger than on Thursday.
Sanders suggested that Clinton was not prepared to take the kind of bold steps he favors to bring fundamental change to the political system. Clinton said she has big, bold ambitions as well, and questioned whether Sanders has the political skills needed to turn proposals into concrete action.
This too was a window into what remains a fundamental divide between the two Democrats: what Sanders calls a political revolution vs. Clinton's advocacy for a more incremental approach to change. Those differences were once debated in relatively polite terms. Now they have become points of annoyance and resentment between the two.
Thursday's debate came five days before what could be a pivotal primary here in New York. Polls show Clinton leading Sanders by low double digits while both the rules and the demographics of the Empire State clearly favor the former secretary of state.
Clinton has consistently done better in primaries than in caucuses. She performs better in states that do not allow independents to vote. And she has an advantage in states with higher percentages of non-white voters. All three exist in New York, which is why Sanders has been in an uphill battle from the start.
A clear Clinton victory Tuesday would stop Sanders's winning streak at seven and, more significantly, make it ever harder for him to overtake her in the pledged delegate count by the time the primaries end in mid-June. He currently trails her by about 250 pledged delegates.
She holds a substantial lead among those dubbed superdelegates, but the key to Sanders's strategy is overtaking her in pledged delegates. That will become increasingly difficult. After New York, 65 percent of the Democratic pledged delegates will have been allocated.
One third of the remaining 35 percent will be awarded by California and New Jersey on the next-to-last primary day of the year. Sanders could win some states in the month of May, but, overall, the terrain could be discouraging for him and his supporters.
The senator from Vermont picked up a significant victory in Wisconsin on April 5 and could have come into his native New York with real momentum. But he was thrown off stride when he charged that Clinton lacked the judgment and qualifications to be president. Sanders claimed that he was only responding to her suggestions that he was not qualified to serve in the Oval Office and felt the need to fight back, but the episode slowed him down when he needed to be moving ahead.
Those exchanges also highlighted the degree to which the Democratic race has grown raw in its later stages and also highlighted the apparent animosity that now exists between the two candidates. After a long season of primaries, caucuses and debates, nerves are frayed and tensions between supporters of the two campaigns have increased noticeably.
Sanders's big and rambunctious rally in Manhattan's Washington Square Park on Wednesday night underscored how disenchanted many of his supporters and surrogates are with Clinton and what her campaign represents to them. Before Sanders took the stage, speaker after speaker described it as the epitome of establishment politics, small-bore ambitions and ties to the moneyed forces of the Democratic Party.
Meanwhile, Clinton's supporters have grown weary of Sanders's attacks, thinking he has stretched the record for his own political gain. She would prefer to begin to focus more on Donald Trump, Sen. Ted Cruz and the Republicans, but she can't quite shake this senator.
All that came together in Brooklyn on Thursday night with the kind of debate that New York has seen in times past. What happens Tuesday won't end the debate. It may shift the conversation about the state of the delegate race, but for now, Clinton and Sanders remain on a personal collision course.