When the Supreme Court considers Donald J. Trump’s sweeping claims of executive immunity on Thursday, it will break new legal ground, mulling for the first time the question of whether a former president can avoid being prosecuted for things he did in office.

But in coming up with the argument, Mr. Trump used a tactic on which he has often leaned in his life as a businessman and politician: He flipped the facts on their head in an effort to create a different reality.

At the core of his immunity defense is a claim that seeks to upend the story told by federal prosecutors in an indictment charging him with plotting to overturn the 2020 election. In that indictment, prosecutors described a criminal conspiracy by Mr. Trump to subvert the election results and stay in power.

In Mr. Trump’s telling, however, those same events are official acts that he undertook as president to safeguard the integrity of the race and cannot be subject to prosecution.

In many ways, Mr. Trump’s immunity claim is breathtaking. In one instance, his lawyers went so as far as to say that a president could not be prosecuted even for using the military to assassinate a rival unless he was first impeached.

But the wholesale rewriting of the government’s accusations — which first appeared six months ago in Mr. Trump’s motion to dismiss the election interference case — may be the most audacious part of his defense. It was certainly a requisite step his lawyers had to take to advance the immunity argument.