"He’s a good man. He will be confirmed and he deserves it," Priebus told ABC's Martha Raddatz in an interview on "This Week" Sunday.
In 1986, Sessions was denied a federal judgeship following allegations that he had called the ACLU and the NAACP "un-American" and made racist remarks directed at colleagues.
The NAACP released a statement calling Sessions' nomination "deeply troubling."
"Based on the disdain for our nation’s civil rights laws that Senator Sessions has consistently demonstrated throughout his career, his fitness to be the chief protector and enforcer of them falls into dire question," the statement said. Sessions denies the allegations to this day.
"This is something that happened that 30 years ago," Priebus said. "This is something that I think is very political, very unfair, and I would hate to be judged -- and I think you would, and everyone out there -- to be judged over a phrasing of one single thing that I’ve said."
Priebus also addressed Trump's meetings with high-profile figures yesterday, including former GOP presidential nominee and governor of Massachusetts Mitt Romney, at his estate and golf club in Bedminister, New Jersey, telling Raddatz part of the purpose of the meeting was to help bring the country together.
"Bringing people in that were once rivals, saying, 'Let's lead together. Let's talk about the future of our country.' They did talk about opportunities for Governor Romney."
Priebus wouldn't rule out the possibility of Romney serving in a Trump administration, telling ABC's Martha Raddatz "anything is possible" when asked how likely it is the former Republican presidential candidate could be nominated for secretary of state.
But, he also noted there are other people still in the running for the post, including former New York City Mayor and loyal Trump ally Rudy Giuliani and South Carolina Gov. Nikki Haley.