Former Vice President Joe Biden dominated the debate stage and weathered the attacks of nine opponents for the Democratic presidential nomination Wednesday night, emerging the clear winner and standing by his promise to not be “overly polite.”

In possibly the most contentious Democratic primary debate thus far, frontrunners Biden and Sen. Kamala Harris of California sparred with each other and the other candidates over the issues of health care, immigration, race relations and climate change.

Following Harris’ and Biden’s heated exchange over busing to achieve school integration in the first debate, Biden was far more aggressive than in his previous debate performance in responding to attacks from every candidate on stage.

DOUG SCHOEN: FIRST DETROIT DEMOCRATIC DEBATE’S KEY WINNERS AND LOSERS (PLUS ONE TERRIBLE TREND)

The former vice president delivered his message compellingly and convincingly. Even during his less strong moments, Biden remained the focal point of the conversation, speaking for over 21 minutes – more than any other candidate on stage.

On health care, in particular, Biden displaying his in-depth policy knowledge while also rebutting repeated attacks from Harris. Biden gave a strong defense of his pragmatic plan to strengthen ObamaCare, while the confusion and lack of clarity around Harris’ plan hindered her position.

Biden also successfully took aim at what he has called Harris’ “have it every which way approach.”

Health care “is the single most important issue facing the public,” Biden said to Harris. “To be very blunt ... you can't beat President Trump with doubletalk on this plan.”

Darkhorse candidate New York City Mayor Bill de Blasio focused his efforts on attacking Biden directly, particularly during the discussions over immigration and race relations. But the attacks failed to create the searing moment that de Blasio had hoped for and did not seem to damage Biden in any meaningful way.

On another front, Rep. Tulsi Gabbard of Hawaii scored points against Harris while addressing criminal justice reform and race. Gabbard took aim at the racial implications of Harris’ tough-on-crime record as a California attorney general, leaving Harris without a rebuttal on an issue that the senator commanded during the last debate.

Despite Biden’s strong performance and solid frontrunner status, it is clear that the party has seismically shifted away from the centrist Democratic Party of the 1990’s, making his path to the nomination far from certain.

Gabbard told Harris: “When you were in a position to make a difference and an impact in these people's lives, you did not and worse yet in the case of those who are on death row, you blocked evidence from being revealed that would have freed them until you were forced to do so.”

“There's no excuse for that and the people who suffered under your reign as prosecutor, you owe them an apology,” Gabbard added.

At best, Harris met expectations but fell short of being the focal point of the night as she was at the debate last month.

The only substantive losers were minor candidates such as Sen. Kirsten Gillibrand of New York and Washington Gov. Jay Inslee. Both have consistently polled at or below the 2 percent threshold and did not get the debate moment that they likely needed to enhance their candidacies in order to qualify for the next round of debates.

Although businessman Andrew Yang did not have a resounding debate moment, the universal-basic-income advocate will likely still secure a spot in the fall debates due to the strength of his grassroots support.

Moreover, despite Biden’s strong performance and solid frontrunner status, it is clear that the party has seismically shifted away from the centrist Democratic Party of the 1990’s, making his path to the nomination far from certain.

Though Biden controlled this debate in many ways, his two leading opponents were absent from the stage of the CNN debate in Detroit. Sen. Bernie Sanders of Vermont and Sen. Elizabeth Warren of Massachusetts, both competing for the support of the far left, debated Tuesday night.

CLICK HERE TO GET THE OPINION NEWSLETTER

Under attack for being too moderate, Biden delivered a powerful response when asked how he can appeal to progressives in the Democratic Party. He drew on his past success in winning elections and scoring major achievements in governing during his long career and emphasized his clear appeal to Midwest and working-class voters.

“I was asked to manage an $87 billion plan that would be spent in a total of 18 months that revived this state and many others … and it kept us out of a depression,” Biden said, referring to his work as vice president to help the auto industry and the country as a whole climb out of the Great Recession shortly after he took office with former President Barack Obama.

CLICK HERE TO GET THE FOX NEWS APP

Biden said he led the economic recovery effort with just a fraction of 1 percent waste or fraud, “and our administration pushed bailing General Motors out saving tens of thousands of jobs here in this state.”

Ultimately, the strength of Biden’s performance made it clear that he is prepared to combine the policy knowledge and experience necessary to take on President Trump and potentially win in November 2020. He clearly remains the candidate who will be tough to beat for the Democratic presidential nomination.

CLICK HERE TO READ MORE FROM DOUG SCHOEN.