With 10 Democratic presidential candidates and five debate moderators on each of two nights, June 26 and 27, each contender will get only a few minutes of talk time (accounting for question time, introductions and closing remarks). Viewers may not get much time to figure out the policy differences among candidates, especially when most agree on most issues, but they will get to see their demeanor, temperament and intellectual acuity.

If the moderators are skilled, they might be able to suss out some real contrasts in the contenders’ views and approach to governance.

The first night features, among others, Massachusetts Sen. Elizabeth Warren, advocate of “Medicare for All,” and Minnesota Sen. Amy Klobuchar, advocate of expanding access under the Affordable Care Act and addressing high drug prices. Ask each what’s wrong with the other’s approach, and ask them both how they get past recalcitrant Republicans. Warren wants free college, and Klobuchar says no way. Have each make her case.

Beto O’Rourke has one of the skimpiest records, while Washington Gov. Jay Inslee (as a congressman and two-term governor) has one of the most impressive ones. Ask O’Rourke why he thinks Inslee, who has done many of the things O’Rourke talks about (universal access to health care, education reform, green-energy initiatives) isn’t a better choice; ask Inslee why his green-energy plan is stronger than O’Rourke’s.

Night two will have on stage four of the heaviest hitters (former Vice President Joe Biden; South Bend, Indiana, Mayor Pete Buttigieg; and Sens. Bernie Sanders of Vermont and Kamala Harris of California). There will be plenty of opportunities to reveal the contenders’ strengths and weaknesses. Moreover, it’s a rare chance to get candidates to confront one another on areas of disagreement.

Biden and Sanders should each explain why it’s a good idea to elect a septuagenarian. Will they release their complete health records by the end of the year? Ask Buttigieg to be candid: Isn’t there a lot he doesn’t know that he’d have to learn on the job?

Sanders has achieved a fraction of what Biden has accomplished. Why choose someone who’s never delivered on his radical agenda over someone who’s made significant, albeit limited, progress on a range of fronts?

Buttigieg defends capitalism but acknowledges its imperfections. Let him and Sanders make the case for democratic capitalism and democratic socialism, respectively. (Will Buttigieg remind Sanders that President Franklin D. Roosevelt thought he was saving capitalism and hence is not the socialist role model Sanders paints him to be?)

Harris and Biden should go back and forth on the 1994 crime bill. Was it a necessary response to rampant crime with unintended consequences or a misguided effort that did more harm than good?

What does Biden know from his years in the Senate and the Obama administration that the others don’t? What does Buttigieg know from his time in the military that the others miss?

On some issues, most of the 20 candidates say the same thing (“end long wars”; “stand up to China without hurting Americans”) but don’t say how they’d do it. Push each one to explain how they would end wars without giving terrorists safe havens. If a tariff war isn’t working against China, should we, for example, revive the Trans-Pacific Partnership, which put China at a political and economic disadvantage in Asia? On repairing the damage President Trump has done to our constitutional democracy, ask them to identify a few reforms for the Justice Department and for intelligence oversight.

The idea should be to let the candidates do most of the talking and, gosh, maybe even debate one another now and then.