With the Arpaio pardon, Donald Trump has demonstrated that he believes the rule of law to be whatever he says it is—and, specifically, that if one of his own political allies runs afoul of our nation's laws, he will simply nullify them.
This gives his own political compatriots ample reason to believe they can break whatever civil rights laws or other federal prohibitions they might feel are standing in their way. It is also, from this repulsive and sociopathic would-be leader, expected. It has been long apparent that Donald Trump is motivated solely by what benefits Donald Trump; he considers loyalty to himself to be the only test of a person's worth, and is motivated to action only in cases where he, himself, believes he will gain from the exchange.
Like his interference in the federal probe into Russia's influence in his election and in his campaign, we new have learned that he sought to use the powers of the federal government to protect his campaign ally even before Arpaio went to trial.
The president asked Attorney General Jeff Sessions whether it would be possible for the government to drop the criminal case against Arpaio, but was advised that would be inappropriate, according to three people with knowledge of the conversation.
After talking with Sessions, Trump decided to let the case go to trial, and if Arpaio was convicted, he could grant clemency.
So the president waited, all the while planning to issue a pardon if Arpaio was found in contempt of court for defying a federal judge’s order to stop detaining people merely because he suspected them of being undocumented immigrants. Trump was, in the words of one associate, “gung-ho about it.”
So Trump first pressured the government to simply drop the case against a campaign ally suspected of violating federal laws; when he got pushback, he let the process play out and then nullified the result personally, with his own pen. Because he wanted to. Because the criminal was a political ally—someone he knew personally—and for no other reason.
It seems as if this dynamic will be coming up again, in this administration. And again. And again. Despite vague mutters of perhaps-disapproval from his fellow Republican leaders, not a one of them has suggested that they will lift a single finger to oppose such moves; from his perspective, this experiment has proven an unquestionable success.
He has tested the waters of whether he can nullify American laws on behalf of his own allies, cronies, or family; the feedback so far indicates he can do precisely that.