TV duel on Friday morning Can Biden deliver? And can Trump pull himself together?

Friday night will show whether Biden can deliver in the presidential debate and whether Trump is capable of discipline. From an observer's point of view, one thing is particularly important for Biden.

Rarely has a US presidential candidate had as much material to use against his rival in a televised debate as incumbent Joe Biden. Former President Donald Trump has been convicted of 34 counts of a felony, and is charged with three other counts of other serious charges.

As president, Trump nominated three of the U.S. Supreme Court justices who voted to overturn Roe v. Wade, restricting access to abortions in America. And as plans for a second term in office, Trump has announced that he intends to retaliate against political enemies in the Democratic and Republican parties.

But it's unclear whether Biden, at 81, is physically or mentally capable of putting Trump in his place verbally. There is actually nothing more important in this debate than the amount of energy and strength Biden shows on stage. The debate will take place on Thursday at 9 p.m. local time (3 a.m. on Friday our time) in a CNN studio in Atlanta.

The debate will last 90 minutes. Not only Trump, but also Biden has weaknesses that his rival can exploit. Both candidates will face a huge audience. Viewers will not see another debate on the US presidential election until September. Every mistake or success in this edition therefore gains in importance.

Can Biden deliver?

The 78-year-old Trump and his Republican allies have consistently mocked Biden for lapses that appear to be linked to his age. The Trump camp has raised the question of whether Biden will be able to last the entire 90 minutes of the debate and stay awake at all.

Representatives of Biden's Democrats hope he can present the same energy he demonstrated during his State of the Union address earlier this year. But a pre-written speech to Congress is very different from a live televised debate with a rival who doesn't shy away from verbal attacks. The Biden team knows that the president cannot afford a bad performance.

Can Trump be boring?

Because his voter base is already firmly behind him, Trump has an opportunity to win over undecided and moderate voters who helped Biden win four years ago and now have concerns about both candidates.

But to win over these voters, Trump cannot simply rely on his usual tactics in appearances, which usually include personal insults and conspiracy theories. Instead of making more statements about planned retribution or lying about the US electoral system, Trump would need to offer a more optimistic vision of the future and draw a clear contrast with Biden on classic issues such as healthcare and education.

In short, Trump must be bored somehow at the debate. Can he be disciplined? Some of his allies have hope in this regard. But looking at how things have gone in the past, they may be disappointed.

Can Trump skirt conviction?

Trump's extraordinary legal problems provide both opportunity and risk for both candidates on stage. The Biden campaign team has signaled an increasing willingness to highlight Trump's conviction in the New York hush money trial.

Biden has so far largely refrained from addressing Trump's prosecution to avoid the appearance of political interference. Trump has been claiming for years, without providing evidence, that Biden is having him prosecuted. At the same time, Biden knows that Trump could attack his son Hunter.

Trump already did this four years ago. Hunter Biden was recently found guilty on three felony counts related to the purchase of a firearm. Trump has also questioned Hunter Biden's foreign business dealings during Joe Biden's tenure as US Vice President.

How does it work with the microphones?

As is so often the case, the moderators and the rules set for the debate are likely to shape the outcome. The rules for this duel are unusual: the candidates forgo the traditional structure for such presidential debates and instead adopt mutually agreed rules and conditions.

Biden and Trump will debate in a studio without an audience and will not make any opening statements. The microphone of the candidate whose turn it is not to speak is muted. No props or pre-written notes will be allowed on stage. Biden and Trump are only given a pen, a notepad and a bottle of water. It was decided by a coin toss that Trump would be the last to make a final statement.

The event will be moderated by CNN anchors Dana Bash and Jake Tapper. Both are known for not letting Trump's lies and conspiracy theories stand. Both have also reported critically on Biden. However, the Biden camp is likely to hope that Bash and Tapper will actively help to immediately reject any lies Trump may have told.

What about abortion and immigration?

While style is sometimes more important than substance on the debate stage, both candidates have to be prepared for political hot potatoes they could be confronted with.

The biggest issue for Trump is abortion. His nominations to the US Supreme Court have enabled him to overturn abortion rights, leading to restrictions on abortion being introduced across the country.

Trump has repeatedly spoken proudly of his role in overturning the law. Biden is likely eager to highlight Trump's role. For the president, on the other hand, the biggest political weakness could be the issue of immigration. His government has found it difficult to curb the number of immigrants entering the country across the border from Mexico.

Biden allies have admitted behind the scenes that Biden is vulnerable on this issue ahead of the US election. Trump loves to point out illegal immigration. He is therefore likely to attack Biden on the issue during the debate. Biden could also face tough questions about his approach to the war between Israel and Hamas.

He has alienated some potential supporters with both his strong support for Israel and his occasional criticism of Israel. The debate provides him with an opportunity to defend his policies on this complicated issue. But it won't be easy.