WASHINGTON — In a break from President Donald Trump, Sen. Rob Portman said Tuesday it would be a "mistake" for the administration to argue that auto imports pose a national security threat to the United States, a move that would clear the way to levy tariffs on imports of cars and car parts.

"Autos help run our economy," the Ohio Republican, a former U.S. trade representative under President George W. Bush, told a gathering at the conservative Heritage Foundation. "They don’t run a national security risk."

Such tariffs could add $2,000 to the average price of a car and cost the jobs of 624,000 Americans, he said.

The U.S. Department of Commerce has launched an investigation into whether imports of autos and auto parts are damaging U.S. national security. If the administration concludes they do harm national security, President Donald Trump can impose tariffs under a 1962 law known as Section 232.

But Portman is pushing for congressional passage of a bill he co-sponsored that would make it harder for presidents to cite national security as an excuse to impose tariffs on imports that have little to do with the military. He said his proposal would return Section 232 "back to its true purpose," which he said were "true national security situations."

"It is a mistake for us to misuse 232, whether for autos or other products," Portman said, warning that other countries will respond with "higher tariffs" on U.S. exports, such as agriculture products.

Portman pointed out that until Trump this summer cited Section 232 to impose tariffs on imports of steel and aluminum from Canada and the European Union, the law had only been invoked twice before, both "with regard to oil."

Under Portman’s bill, the Pentagon — not the Commerce Department — would have to determine whether an import threatens national security. Portman said the Pentagon disagreed with the Trump administration’s claim this summer that steel and aluminum imports were threatening national security.

In addition, if an administration went ahead with tariffs, there would be "an opportunity to go back to Congress for a motion of disapproval," Portman said.

The bill is co-sponsored by Republican Joni Ernst of Iowa and Democrat Doug Jones of Alabama.

Under a revised North American Free Trade Agreement with Canada and Mexico there is a commitment to avoid using national security tariffs. But there is no guarantee an American president will turn to tariffs in the future.

Portman reminded the audience that Canada responded with $12 billion worth of tariffs on U.S. goods, "including agricultural products from Ohio, my home state."

Portman said when "you have this escalation of tariffs," it is "not good for either country."

jtorry@dispatch.com

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