Arpaio, 85, who once led the Maricopa County sheriff's department, was found guilty last month of criminal contempt for violating the terms of a 2011 court order in a racial profiling case. It argues that Arpaio should not be sent to prison for "enforcing the law" and "working to keep people safe".
"When you talk about a justice system that was so negligent, the Obama administration set up Joe Arpaio on day one - and that's hardly an application of the rule of law".
But despite his long tenure as sheriff of Maricopa County, Arpaio lost the support of his constituents previous year, defeated by Democrat Paul Penzone in the elected position.
On his official Twitter account, Arpaio thanked Trump and denounced his conviction as a "political witch hunt" by "Obama holdovers".
On "The Five" tonight, Ed Henry said this move may "shock" and "horrify" some lawmakers on Capitol Hill, but Trump supporters are going to "love" it.
Arpaio is "a worthy candidate for a presidential pardon", it added.
The announcement still came as a shock for many. John McCain showed a "very presidential" restraint. He declined to say if he would run again for sheriff. "He should have served his time", said Democratic Congressman Joaquin Castro.
Of all the inhumane policies Arpaio instituted and participated in, it was the immigration patrols that landed him in hot water.
Many believe that a pardon could open the door for other white nationalists and law enforcement officers who may use discriminatory practices to violate the civil rights of Latinos or African Americans.
Joe Arpaio, 85, was found guilty of wilfully violating a 2011 injunction barring his Arizona officers from stopping and detaining Latino motorists exclusively on suspicion they were in the USA illegally. "And I'm going, 'What about some of the Republican leaders that are right there with the obstructionist Democrats?' Trump was being so nice, I thought, last night [too nice]".