Miami (CNN) Joe Biden is no stranger to the presidential debate stage, but tonight marks the first time he steps foot on that stage as a frontrunner for the Democratic nomination.

Biden, who watched last night's debate in Delaware, will appear on stage with more presidential-level debating experience than his Democratic opponents. His first presidential debates came in the 1988 campaign, but that race also brought a debate moment which helped dash his presidential hopes when Biden used similar language in his closing remarks as British politician Neil Kinnock.

The Delaware Democrat returned to the presidential debate arena for the 2008 campaign when he debated candidates like then-Sens. Barack Obama and Hillary Clinton. During a 2007 Democratic debate, he also unleashed a memorable zinger against Republican presidential candidate Rudy Giuliani.

"There's only three things he mentions in a sentence -- a noun and a verb and 9/11," Biden said to laughter. "I mean there's nothing else. There's nothing else."

But tonight marks Biden's first debate in seven years. In 2012, Biden sparred with Republican vice presidential nominee Paul Ryan. Biden's strong performance, which included several instances of calling out Ryan's talking points as "malarkey," quelled some Democrats' concerns after President Barack Obama's lackluster first debate against Mitt Romney one week prior.

Biden also delivered a memorable debate performance in 2008 when he faced off against GOP vice presidential nominee Sarah Palin, who approached her Democratic opponent at the onset with the question, "Can I call you Joe?"

Biden grew emotional as he talked about the loss of his wife and young daughter more than 30 years prior.

"The notion that somehow, because I'm a man, that I don't know what it's like to raise two kids alone, I don't know what it's like to have a child that you're not sure is going to make it. I understand," Biden said choking up.

As he readies to take center stage at the first Democratic primary debate in Miami, the former vice president hunkered down with advisers in Delaware this week for "comprehensive" debate prep, which has included holding mock debates, a source familiar with his preparations said.

For weeks, Biden has blocked off time for debate prep on his schedule while on and off the campaign trail, according to sources familiar with his preparations, reading through briefing books and participating in question and answer sessions.

But preparations picked up in earnest this week with Biden and his advisers huddling for several days for what his team describes as "debate camp." Former Michigan Gov. Jennifer Granholm, who stood in as Palin in Biden's debate prep for the 2008 vice presidential debate, is among those helping Biden prepare, one source said, adding Granholm can't endorse a candidate due to her role as chair of American Bridge.

"I am preparing and basically looking at less about what the other people are for or against and trying to figure out how I can get to the place where I can communicate to the American people what I believe, why I'm running and why it's important," Biden told reporters in Eldridge, Iowa, earlier this month.

Biden will be appear on stage tonight with a number of Democratic rivals who have taken aim at the former vice president since entering the race, but it remains unclear whether his opponents will use their limited time in this debate to try to make dents in Biden's argument.

Bernie Sanders , who will be standing to Biden's right, could try to paint Biden as a middle ground candidate, as he has done on the campaign trail in recent weeks. South Bend, Indiana, Mayor Pete Buttigieg , who is nearly four decades younger than Biden and will be to his right, could attempt to make a generational argument. Sen. Kamala Harris has gone after Biden on criminal justice issues in the past while Andrew Yang has jabbed at Biden on multiple fronts.

Biden's recent comments about working with segregationist senators, which resulted in a public dispute with Cory Booker, could also be a topic of discussion.

Biden has studied his own record, preparing for possible attacks that might come his way, and he's watched some of Sanders' exchanges with Hillary Clinton in 2016 to familiarize himself with the Vermont senator's style.

"It's an exaggeration to suggest that there's going to be any real depth about what we're going to be able to get into in a minute," Biden said earlier this month. "And so my guess is it's going to be an inclination instead of talking about the future, it's going to be talking about the past, and I'm about the future not the past."

The often verbose Biden is keenly aware of the strict time limits for tonight's debate, telling reporters earlier this month it's "like a lightning round." The candidates will have one minute to respond to a question and 30 seconds for a follow up as warranted.

During the 2008 campaign, one debate moderator noted Biden's "gaffe prone" and verbose tendencies and asked, "Can you reassure voters in this country that you would have the discipline you would need on the world stage senator?"

Biden responded succinctly, "Yes."