"President-elect Trump's choice of Steve Bannon as his top aide signals that white supremacists will be represented at the highest levels in Trump's White House," Reid spokesman Adam Jentleson said in a statement Sunday.
The ADL opposes the appointment of Bannon because the alt-right movement, which he is sometimes credited with fostering, is "so hostile to core American values," the group's CEO, Jonathan Greenblat, said in a statement to the media.
"It is a sad day when a man who presided over the premier website of the alt-right — a loose-knit group of white nationalists and unabashed anti-Semites and racists — is slated to be a senior staff member in the 'people's house,'" Greenblat's statement read.
But Priebus said that, based on his experience, such categorizations of his colleague were unfounded.
He said he found Bannon in person to be "the opposite" but didn't clarify what he and Bannon discussed that countered such descriptions of him. Priebus recommended that Americans give Bannon time to prove his character.
"Look at the person. Get to know the person. This is a very, very smart person," Priebus said.
Priebus didn't mention immigration this morning, but in a "60 Minutes" interview that aired Sunday, Trump said he planned after his inauguration in January to immediately deport 2 million to 3 million undocumented immigrants who "have criminal records."
He said Trump put his resources into the states that would get him elected and declined to campaign in highly populated states like New York and California, which he said could have bolstered his numbers there.
"This is an election that takes place in about 12 states," Priebus said. "He played the states he wanted to play."