Story highlights Julian Zelizer: Tweets reveal a great deal about what Trump thinks of scandal

These 140-character commentaries offer troubling signals of what's ahead, he says

Julian Zelizer, a history and public affairs professor at Princeton University and a CNN political analyst, is the author of "The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society." He's co-host of the "Politics & Polls" podcast. The opinions expressed in this commentary are his own.

(CNN) President Donald Trump blasted off two more angry tweets Thursday morning in response to the appointment of former FBI Director Robert Mueller as special counsel to oversee the federal investigation into Russian interference in the 2016 election.

Julian Zelizer

Sometimes tweets are more than tweets. When they come from POTUS, they appear as not only the rants of the most powerful leader in the free world, but they can also tell us a great deal about the state of mind of the commander in chief.

In the first tweet , the President wrote: "With all of the illegal acts that took place in the Clinton campaign & Obama administration, there was never a special counsel appointed!"

This tweet was classic Trump. The message was angry, it was defiant and it appealed to his supporters' sense of being victims -- that the political system was out to get their leader in a way that Democrats have never encountered.

The tweet also reveals a great deal about what the President is thinking as this scandal has evolved into a serious political crisis that could jeopardize the future of his administration. For starters, he initially spelled counsel as "councel." Certainly spelling has never been Trump's greatest skill, but sometimes such a mistake tells us a great deal about how someone is thinking about a situation. The fact he made such a mistake suggests that, still, even after everything that has happened, nobody is monitoring him. The White House advisers are either continuing to let him run wild, or he is refusing to listen. With legislators and lawyers investigating, this ongoing lack of supervision and self-control can be dangerous on many levels.