President Trump might say that his pardon of conservative author Dinesh D'Souza is about correcting an injustice. But it isn't. This pardon is motivated by Trump's desire for a catharsis and to fire a political warning shot at special counsel Robert Mueller.

By pardoning D'Souza, Trump can flex his executive branch muscles and comfort himself as to other issues beyond his control — specifically, the ongoing special counsel investigation and the president's evident displeasure with Attorney General Jeff Sessions are obviously issues that grate on the president's psyche. By pardoning D'Souza of his conviction for using straw donors to exceed political donation limits — a man who few independent legal analysts believe deserves a pardon — Trump waves his power in his opponents' faces in a manner that he knows will anger them. That angry reaction will please Trump, who thrives on the idea of his own untrammeled power and the figurative explosion of his enemies' heads.

This pardon also clearly seems targeted specifically at special counsel Robert Mueller and the president's desire to let Mueller know that he will use his executive power to protect those close to him. In his tweet announcing D'Souza's pardon, Trump claimed that the author "was treated very unfairly by our government!" That language sits perfectly alongside Trump's ongoing narrative towards what Trump believes is Mueller's "witch hunt" targeting his administration.

This pardon is Trump's way of painting himself as the "witch hunt" destroyer: the leader who can ensure that injustice against those around him is prevented. But it also serves one subtle broader purpose: delegitimizing the rule of law as it affects his administration. Trump's consistent message in relation to the special counsel and FBI is now one of absolute scorn: the president wants his base to believe these institutions are inherently political and out to get him at all costs. Trump is banking that if he pushes that message enough, he can weaken the moral and legal credibility of any prosecutions yet to come.

Ultimately, Trump will likely attempt to pardon those convicted by Mueller's prosecution. And at that point, a constitutional crisis really will be underway.