Bush, widely considered a presidential contender in 2016, said earlier this month that even though people who immigrate illegally to the United States are breaking the law, he doesn't always consider that to be a felony.
"It’s an act of love. It’s an act of commitment to your family," he said at the time. "I honestly think that that is a different kind of crime that there should be a price paid, but it shouldn’t rile people up that people are actually coming to this country to provide for their families."
"I hold no brief for Jeb Bush, but having such a prominent Republican speak so humanely and unapologetically about the motivations behind many of those who have come to reside in this country is good for all of us," Flake wrote Monday on his Facebook page.
"Growing up here in Arizona, I’ve seen what motivates those who come here illegally," he added. "Sure, some come with the intent to do harm or simply to take advantage of our generosity. But many come to find work to feed their families. To lump everyone who crosses the border illegally into the same class is unfair and unproductive."
But regardless of immigrants' motivations, Flake argued, strengthening border security and beefing up temporary worker programs must remain as top immigration reform priorities.
"Truth is, I agree with Jeb, and I applaud him for having the guts to say it," he wrote.