Whenever you buy from aboard, that's money and jobs that are lost to the USA.
So they want to export, but not to import!
And instead of banning the imports, they just set technical standards.
Like requiring specific bumpers and car height, and pollution standards, despite the fact US roads are deadlier and the US pollutes more than anywhere else.
Other countries are a bit more optimistic about international trade, and recognize they can't do everything.
Western Europe, for exemple, has focused on high added value engineering and office jobs, to outsource production to Eastern Europe and Asia. And everyone has an engineering degree in here, so good luck to live on your factory job.