Todd Graham is the director of debate at Southern Illinois University. His debate teams have won five national championships, and he has been recognized three times as the national debate coach of the year. Follow him on Facebook and Twitter . The views expressed in this commentary belong solely to the author. View more opinion at CNN.

(CNN) Rising like a phoenix from the ashes of his previous debates, former Vice President Joe Biden met one of the most pivotal moments of his career with his best debate ever. Meanwhile, Vermont Sen. Bernie Sanders fell flat, failing to rise to the occasion.

Amid the novel coronavirus crisis that has gripped the nation -- and the world -- the two Democratic presidential contenders were grilled on how they would handle the pandemic and while Biden was ready with strong, thoughtful responses, Sanders left much to be desired on the debate stage.

A

Joe Biden

Biden highlighted how the coronavirus pandemic is a national emergency, topically crafting all his answers to the moderators' questions. Using examples (an important debating tool), Biden explained how his approach to dealing with both the health aspect and the financial aspect of the crisis would get us through this tough time.

On health, when asked if he'd use the military to fight the virus, Biden was direct in saying he would, just like during the Ebola crisis. He mentioned specifics : the military has "the capacity to build 500-bed hospitals" where they are needed. And Biden did well to highlight the responsibility of the federal government to anticipate "what will happen in the next month or weeks in terms of the flow into the health care system by bringing the military along."

Biden focused his responses on getting the "first things first" while providing "help to those places which are the most vulnerable." He compared and contrasted his ideas with both Sanders and President Donald Trump (another valuable debating technique). For instance, when Sanders highlighted the benefits of a Medicare for All health care system for handling the crisis, Biden countered with the example of Italy. It has a single-payer health care system and its people are in real trouble right now after the nation went on lockdown. As Biden said about Medicare for All: "That would not solve the problem at all."

On the financial aspect of the crisis, Biden's presentation was the opposite of Trump's Oval Office address last week. Touching on fears of the financial burden the virus could impose on citizens, he was clear, concise, and direct, saying, "We just pass a law saying that you do not have to pay for any of this, period." In contrast to Trump's uneven policies, Biden mentioned having "one voice" and a "common plan." He criticized our current ability to respond financially due to Trump's "godawful tax cut of 1.9 trillion," which has, "eaten a lot of our seed corn here." Biden's point about needing to "level with the American people" was a direct criticism of Trump's handling of the situation and Biden wisely ended the debate by addressing the need to keep people in their homes and make sure they don't miss mortgage payments.

In addition to the coronavirus discussion, Biden seized the moment on stage to declare, "I'll pick a woman to be vice president. There are a number of women who are qualified to be president tomorrow." What a way to seal the debate!

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Bernie Sanders

Beware the ides of March. Too often, Sanders' answers pivoted to his generic campaign ideas, as opposed to focusing on the moment, the question or the mood of the American people.

First, questions are not arguments. When posed by the debater, they simply aren't a reason to vote for him. Unfortunately for Sanders, he doesn't understand this basic debating fact. When addressing the many issues that face individuals affected by coronavirus Sanders asked: "Who's going to get food to (the elderly)? How do we get food to them?"

That was followed by four more questions before the senator had finished his response to the prompt.

By asking tough questions in a time of a national emergency and then not answering them Sanders employed the worst debating strategy ever. The American public already has those questions. We don't need to elect someone who is also asking them. We need to elect somebody who's answering them.

Could Sanders performance get any worse? Unfortunately, it could, and it did during his closing remarks. When asked what he would say to those people who are concerned about coronavirus, Sanders began with a decent answer about test kits and ventilators, but then pivoted again asking questions.

"It is time to ask this, the question of where the power is in America. Who owns the media? Who owns the economy? Who owns the legislative process?"

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No, it's not time to ask that. This was his answer to the very personal question of what he'd say to the victims of the crisis. My goodness.

If the question of whether Sanders, like Biden, would commit to choosing a woman running mate was an opportunity for Sanders to recover from his less-than-stellar performance on the topic of coronavirus, he let the opportunity pass. The question seemed to catch the senator off guard. Sanders first dodged the question, choosing to make Biden defend his voting record and forcing the moderator to press Sanders for a direct answer. Sanders finally responded with a less than certain, "in all likelihood."