Trump was telling advisers that classified documents belonged to him and that the government could not have them back.

Via: The New York Times:

Mr. Philbin tried to help the National Archives retrieve the material, two of the people familiar with the discussions said. But the former president repeatedly resisted entreaties from his advisers.

“It’s not theirs, it’s mine,” several advisers say Mr. Trump told them.

Classified documents don’t belong to any president, and the dangerous implication in Trump’s comment is that if he believed that the nation’s secrets belonged to him, Donald Trump could do whatever he wanted with them.

Trump could sell them. He could barter them for foreign help in the 2024 presidential election. In his mind, he could do whatever he pleased.

It is that thought process that alarmed the Justice Department into action. The classified intelligence was important enough to Trump that he lied to both the National Archives and the Justice Department, so he must have had plans for the documents.

The investigation into what those plans were will be a determining factor in deciding what if any crimes the US government decides to charge the former president with.