Priebus told CNBC that the president has been a long-term opponent of trade imbalances, but he allowed that tariff threats from the White House may be both a sincere policy to tackle American trade deficits and a negotiating tactic.
"I think it's the type of thing the president wants to do: Put people on their heels, and say 'I'm going to tackle this trade imbalance once and for all,'" Priebus said. "It's something he's talked about since 1980, so it's not like this is a new policy: Everyone likes to talk about populism and nationalism — this is Trumpism."
"His default position is what you're seeing right now," Priebus said of the U.S. president.
According to the former chief of staff, Trump likes to begin negotiations with a hard-line position and then pull back from that tough stance incrementally. He cited how Trump at first proposed tariffs that applied to aluminum and steel imports across the board, but subsequently took Mexico and Canada "off the table."
Asked specifically about China, Priebus cited how the world's second biggest economy sometimes requires importers to transfer proprietary technology to Chinese control — so-called technology transfers. China has weak intellectual property protections, he added.
The bigger problem, Priebus indicated, is how the United States doesn't impose big import duties on products such as cars, but U.S. manufacturers must pay tariffs sometimes amounting to "25 percent, 50 percent" to other countries. Priebus did not name those countries.
Other times, he continued, U.S.-made products have to be shipped overseas in components and then reassembled so that U.S. manufacturers can get around tariffs.
Throughout the interview with CNBC, the former chief of staff had emphatic compliments for his old boss, saying the president "is a force in and of himself, which the Republican Party has benefited from."
Trump announced over Twitter that he had replaced Priebus with John Kelly, a retired four-star Marine general who had been serving as Homeland Security secretary, in July of last year.
Prior to that move, Priebus had become a target of Trump's ire — the president reportedly gave him various deadlines to get a tumultuous White House in order.
Priebus had led the Republican National Committee before coming to the White House — a job he'd held since 2011.
—CNBC's Jacob Pramuk contributed to this report.