Every candidate for the Democratic nomination for president (save one) knows what they need to do: knock former vice president Joe Biden out of the race. Biden himself knows he’s the battleship everyone else needs to sink. He expects the torpedoes. But will anyone launch them?

Attacking Biden is necessary, but it is risky. Each individual candidate would prefer for everyone else to do the attacking and avoid the ire Biden fans will attach to whomever bruises Uncle Joe. All of the candidates have to know, however, that they are prisoners of the same dilemma: They need Biden to trip, but they don’t want to be seen as the one who has stuck out their leg.

The best time to do this, of course, is during the upcoming debates. Candidate Donald Trump benefited from the debates in 2016, how they focused the nation’s attention on specific places at specific times. On the Republican side, we saw then-Govs. John Kasich of Ohio and Scott Walker of Wisconsin make the mistake of “strategic patience” in 2015, as did former Florida governor Jeb Bush. They fought over fundraising, volunteers, endorsements and name recognition, while holding back sustained, focused attacks on Trump for the actual primaries and caucuses. They didn’t realize that the debates themselves had become primaries, primaries they needed to win or at least place in to move forward.

An even greater intensity of focus will be on these Democratic debates. Each one that Biden doesn’t lose, he will win conclusively. Unless he is knocked down, he will be the last candidate standing.

A few members of the Democratic field may hold their fire because their futures look so bright. Sen. Kamala D. Harris (Calif.) has a strong shot at being Biden’s running mate if he makes it through the gauntlet and if she doesn’t screw up. She has the California money and muscle, and she serves to knit the party together. South Bend, Ind., Mayor Pete Buttigieg gains stature with every cool and calm interview and every demonstration of intellectual capacity and rhetorical skill. He has already run far and fast enough to all but guarantee a seat in the Cabinet of the future president if he or she doesn’t end up with a grudge against “Mayor Pete.”

For all of the other would-be nominees, though, this is probably their first and last presidential rodeo. So they have to think seriously about using the debate spotlight to do maximum damage to Biden. Sen. Bernie Sanders (I-Vt.) especially should be throwing hammers at Biden. Biden is the embodiment of the party establishment that collectively conspired to keep the old socialist down while condescending to him throughout 2015 and 2016. Sanders’s supporters are devoted to him. They will cheer a debate slugfest, even if the establishment cringes.

The “moderates” with slight support in polling or low balances in their campaign treasuries have got to swing hard at Biden as well. Former representatives John Delaney (Md.) and Beto O’Rourke (Tex.) and their House colleagues still serving — Reps. Tulsi Gabbard (Hawaii), Seth Moulton (Mass.), Tim Ryan (Ohio) and Eric Swalwell (Calif.) — must all take direct and specific shots at the former vice president. They don’t have time to “introduce” themselves. They either make a mark by leaving a mark on Biden, or they are going to fade quickly. They all should count on one chance, and one chance only, to shine. The ability to score on Biden will foreshadow the same ability to go after Trump; the progressive base, looking for someone who can take on the president, will reward the combative.

Democratic Sens. Cory Booker (N.J.), Kirsten Gillibrand (N.Y.), Amy Klobuchar (Minn.) and Elizabeth Warren (Mass.) have the most to lose by trying to advance without being blamed for hitting Biden hard. They shrink every day they don’t grow. They have the machines and the money. They need to stand out. They need to score.

The remaining candidates may think the prudent strategy is to stay low and hope Biden fumbles the ball on his own. But Govs. Steven Bullock of Montana and Jay Inslee of Washington, former governor John Hickenlooper of Colorado, former San Antonio mayor Julián Castro and, yes, businessman Andrew Yang, also have to torch the debate stage or go home to their states of origin. They and the senators should study what happened in 2016 to GOP Sens. Marco Rubio (Fla.) and Ted Cruz (Tex.), who waited too long. The opportunity to tangle with Trump and become a viable opponent was lost by the time they and Kasich arrived in Florida for the last debate before Iowa. They had fought each other, not Trump.

So, in short, some advice to the Democratic candidates: Don’t take a Wiffle bat to a gang fight. Craft the verbal arrow in advance and aim it at Joe Biden, and hope everyone else does as well.

Read more:

George F. Will: How the Democratic field is winnowing itself

Richard Cohen: Who are all these Democratic presidential candidates?

Helaine Olen: Can Joe Biden’s nostalgia act work?

Paul Waldman: Why Joe Biden?

Jennifer Rubin: Trump’s biggest problems for 2020: Joe Biden and women