Down to Donald Trump's new demand overnight to drop the federal investigation into his efforts to overturn the 2020 election. The former President and his lawyers insisting presidential immunity protects him from prosecution, but that's been up for debate in the courts. Abc's Aikajachi has more on what the former President is saying tonight.

Tonight, Donald Trump doubling down on his lawyers' arguments that he should be immune from prosecution in his federal election interference case. The former President posting on social media, I was doing my duty as President. I did nothing wrong. In a 71-page filing overnight, Trump's attorneys demanding immunity, writing under our system of separated powers, the judicial branch cannot sit in judgment over a President's official acts. Trump's lawyers contend no current or former President should be prosecuted for official acts unless he is first impeached and convicted by the Senate. Congress acquitted Trump in his two impeachments. He has denied any wrongdoing. Trump's lawyers also warning that if the case is taken to trial, it will launch cycles of recrimination and politically motivated prosecution that will plague our nation for many.

Decades to come. They're searching for every opportunity to delay, to make broad sweeping claims, to prevent these trials.

Special counsel Jack Smith alleges Trump acted beyond his official duties as he used deceit toward state officials to subvert the legitimate election results. The US Supreme Court on Friday rejecting Smith's request to fast-track this very dispute over Trump's immunity.

The sweeping claims of absolute immunity, I think, will ultimately, even with this Supreme Court, not hold. But it's going to take a while to get there. That's the problem.

district Judge Tanya Chuckkin, who was overseeing the case, rejecting Trump's immunity argument earlier this month, writing, Whatever immunities a sitting president enjoy, the United States has only one chief executive at a time. Rachel, the appellate court has signaled that it plans to move quickly with oral arguments beginning on January ninth. Still, its decision will almost certainly be challenged in the Supreme Court, potentially delaying the trial's March fourth start date.

Rachel? And of course, all of this playing out against the backdrop of the Republican primary. All right, Ike, thank you.

Hi, everyone. George Stephanopoulos here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights, and watch live event coverage, click on the right over here to subscribe to our channel. And don't forget to download the ABC news app for breaking news alerts. Thanks for watching.