Vice President Pence should do well. His personality, as we’ve seen in his press conferences on COVID-19, is calm, controlled, and steady. Those are attributes that will help him in the debate setting. However, his presence and rhetoric frequently exude a sense of a submissive ‘yes-man’ to a domineering president. Cool, calm, and collected will play well in the debate; obedient and obsequious will not. He must not only appear ready to take over the presidency if necessary, but he needs to show himself to be capable of being a strong leader in his own right, ready to captain his own ship. This will be a departure for Mr. Pence—as it would be for any vice president. That challenge is magnified by the need to walk a fine line between showing personal strength and not rattling a cagey, paranoid president who is terrified of being upstaged by any of his team members.

For Ms. Harris, who showed herself to be an effective and powerful debater during the primaries, it is critical to revise an approach that worked well for her in the summer and fall. Her tenacious, prosecutorial approach to leveling candidates—including Mr. Biden—showed her strength in the political arena. Now, her challenge is to steer away from Kamala Harris, prosecutor, and toward Kamala Harris, president. It would be important for her to focus on the issues that she cares deeply about and would pursue as president. Part of the debate will focus on how she would help Mr. Biden if he is elected president. But the debate performance must also demonstrate who she would be in the absence of Mr. Biden. While America loves a fighter who can match anyone in the political arena (an even more important trait for a female candidate running in a country with significant, remaining gender biases), what America needs right now is a steady, strong, empathetic leader ready to govern independently.