Clarke wrote: "These illegal aliens are not all 'Dreamers' many are straight up thugs."
The former Arizona sheriff later walked back his 2007 comments while giving testimony in a civil lawsuit.
Obama commuted the sentence of the military leaker but did not issue a full pardon.
Speaking to ABC's "This Week," Homeland Security adviser Tom Bossert said that in the wake of Hurricane Harvey the public was not focused on just one person.
Convicted Sheriff Arpaio thanks right wing media for getting his story to Trump.