President Trump tonight repeated his claim that he can declassify something "even by thinking about it."

There's a lot of reasons why that's dubious, but here's an explainer about why it doesn't work that way.

bloomberg.com/news/articles/… A couple precedents worth highlighting, one a century old and the other from the Trump administration itself....

In 1929, the Office of Legal Counsel advised President Hoover that he didn't need to personally sign every pardon -- but that they *did need to be in writing.*