Joe Biden’s advisers have been preparing him for an onslaught. Bernie Sanders is looking to cut a clear contrast on policy. Pete Buttigieg hopes to appear as “something completely different.” And Elizabeth Warren is all but certain to arrive in Miami next week with yet another new plan.

As for the 16 other candidates preparing to take the stage at the first Democratic debates, most can’t wait for a second chance to make a first impression.

“I feel like everyone needs a big moment,” said former Maryland congressman John Delaney, who, like two-thirds of the candidates taking the stage Wednesday and Thursday, has been toiling under the margin of error in most polls. “The debates can make people, and they can also break people. I want to be in the make column.”

Nearly four years after Republicans captivated the nation with a 12-debate series starring Donald Trump that paved the way for a White House win, Democrats will finally get their chance to counterprogram with their own attempt at a ratings blockbuster. Unlike in 2015, when Democrats scheduled two of their three debates on weekends, party leaders have done everything they can to elevate the importance of the event.

Candidates have been digesting briefing books and consuming hours of old debate footage. They have been parrying around the table to get their answers under a minute — an iPhone alarm times Delaney’s answers — or with mock contenders at separate lecterns in the case of Sen. Kirsten Gillibrand (N.Y.). Another candidate, former housing secretary Julián Castro, has rented a lectern in Miami to practice early next week, with his wife and kids traveling to be by his side.

All the preparation will provide Democratic voters desperate for salvation from President Trump a chance to witness two separate presidential candidate faceoffs.

One will take place with five presidential candidates — a former vice president, three senators and a 37-year-old mayor — who have proved in recent months that they can gain traction with voters, drawing crowds, donors and volunteers.

The other debate will be a do-or-die fight to get noticed or go home this fall.

“At the top of the pack, they have to worry about not making any mistakes,” said former Democratic National Committee chairman Howard Dean. “And, at the bottom of the pack, they have to distinguish themselves without being obnoxious.”

The complicating factor is that the 20 candidates competing in both groups will be shuffled across two nights, with four prime time hours divided into hundreds of 60-second answers and 30-second rebuttals, one-line zingers, lightning-fast policy summaries and the occasional barbed attack. All of it will be orchestrated by five moderators between four commercial interruptions each night, while Trump threatens to live-tweet his insults from the White House.

The hunger for clarity, in other words, must first survive quite a bit of televised chaos.

The candidates will not be allowed opening statements, props or prepared notes onstage, but there will be 45-second closing statements, according to debate rules circulated by moderator NBC News. The candidates will get timing lights, water to drink and pens and paper, as well as a chance to use the bathroom during longer commercial breaks. NBC has refused to rule out the possibility of a lightning round, according to multiple campaigns.

The spotlight will burn brightest Thursday for former vice president Joe Biden, who is polling at the top of the pack after weeks of stumbles that have repeatedly prompted the rest of the presidential field to call him out. He has been attacked for supporting a ban on federally funded abortions, before reversing his stance, for his voting record on trade and criminal justice and, most recently, for his boasts about his collegiality with a segregationist senator who described blacks as “an inferior race.”

Biden has been preparing for how to spin the attacks against him with his former chief of staff Ron Klain, who played similar roles in debate preparation for former president Barack Obama and former secretary of state Hillary Clinton, and former Obama adviser Anita Dunn.

He has made clear on the campaign trail how he will try to parry the slings and arrows, constantly seeking to refocus the debate on President Trump and embracing his record of working across party lines. For Biden, the policy differences in the party, over issues like Medicare-for-all, matter less than the commonalities, such as the fact that all candidates support some path to universal health care.

“Of course he is going to get attacked. That is pretty clear,” said Kate Bedingfield, his deputy campaign manager. “But that is going to mean he has more time than the others to talk about his positive vision and accomplishments.”

In that second debate, Biden will be standing next to Sen. Bernie Sanders (I-Vt.), who has made clear that he sees many of the former vice president’s accomplishments as liabilities. Though both men voted for the 1994 crime bill that Biden helped write, their records diverge on many fronts that are likely to be exposed.

“He genuinely has affection for Biden from their time together in the senate,” said Ari Rabin-Havt, the chief of staff of Sanders’s campaign. “But they had a number of votes that are different. It is not unhealthy for Bernie to point out that he was right about the Iraq War, that he was right about the bankruptcy bill. It is not unhealthy to point out that he was right about [opposing] permanent normal trade relations with China.”

Both men will be flanked by two relative newcomers to the national stage: Sen. Kamala D. Harris (Calif.), who has been preparing for the debate with meetings at Washington media firm GMMB, and Buttigieg, the mayor of South Bend, Ind., who spent most of the past week dealing with fallout from the police shooting of a black man in his hometown.

“He wants to present himself as a fresh face that is the complete opposite of Donald Trump both in style and tone,” said Lis Smith, a communications adviser for Buttigieg.

Harris, the former California attorney general who started her campaign strong but has struggled to deliver a distinct message, will get a clear chance as the only woman at center stage to reintroduce her message as a candidate who can prosecute Trump.

Gillibrand is also hoping to stand out in the group, according to an aide who spoke on the condition of anonymity to discuss debate preparations, by arguing that she offers a rare blend of legislative experience, the ability to win Trump counties and bold liberal policies that will stand up to Trump.

Warren will appear on a separate stage Wednesday night, a result of a random drawing that was widely seen as a setback for her, given the possibility of lower ratings. But her position as the sole candidate polling above 5 percent on the stage, flanked by former Texas congressman Beto O’Rourke and Sens. Cory Booker (N.J.) and Amy Klobuchar (Minn.), could allow her to dominate much of the discussion, which, like Thursday’s event, is expected to have a policy focus.

Advisers to multiple campaigns said Booker might prove to be the big winner of the debate sorting, since he will have a clear breakout opportunity to present his vision at the center of the stage a week after going toe-to-toe with Biden over his comments on cutting deals with segregationists.

Booker has boasted in the past over his work with former senator Jeff Sessions of Alabama, who Warren has accused of trying to intimidate black voters early in his career. But he particularly objected to Biden’s recollection that a senator in the 1970s called him “son” not “boy,” a derogatory term for blacks in the segregationist South.

Biden has refused to apologize and has instead asked Booker to apologize for suggesting he was insensitive, effectively elevating Booker’s position in the crowded field.

The X-factor in both debates will be how the lower-polling contenders try to get noticed. This includes several non-politicians, including spiritual adviser Marianne Williamson and businessman Andrew Yang, who are pushing less conventional campaigns. “My dreams are coming true,” Yang tweeted after he made the stage with Biden and Sanders.

Under Democratic Party debate rules, the qualifications for making the September debates have been raised to scoring 2 percent in four polls over the summer and receiving 130,000 donations. Qualifications for next week’s debate and one scheduled for late July were set at hitting 1 percent in three polls or 65,000 donors.

Without a breakout moment in the next couple of months, most likely triggered by the June or July debates, many of the candidates — from New York Mayor Bill de Blasio and former Colorado governor John Hickenlooper to Williamson and Reps. Tim Ryan (Ohio) and Eric Swalwell (Calif.) — may soon find their campaigns prematurely ended.

Some have already telegraphed their plans to get noticed. Hickenlooper has refocused his campaign around a denunciation of “socialism,” a not-so-veiled shot at Sanders, with whom he will share a stage. Delaney has also been going after Sanders for what he calls “dishonest” policy plans, though he signaled this week that he has a different view of Warren, who backs some of Sanders’s key ideas, like Medicare-for-all.

“I actually think Elizabeth Warren and I am the only ones putting forward real ideas,” Delaney said.

An overriding question for the field is whether the candidates will be able to create a debate that attracts the attention of the nation. Democrats have prided themselves on so far conducting a relatively respectful campaign, with few personal or character attacks. Barring a surprise, the Democratic debates might lack some of the shock and awe of the GOP show last time, which is fine for many Democrats.

“At the Republican debate in 2016, they had a literal body part measuring contest onstage,” Rabin-Havt said. “We have serious candidates who are going to talk about serious issues.”