Many domestic manufacturers are pushing for freer trade despite the mounting difficulties some are having with the rising volume of imports, the Wall Street Journal reported.
The manufacturing sector is one of trucking's largest and most important customers.
The Manufacturers Alliance, a research group whose members include large companies such as Caterpillar Inc, has endorsed a multilateral free-trade agreement for the world's manufacturers that would essentially strip away tariffs and combine regional and bilateral trade pacts under one umbrella.
However, many smaller manufacturers have complained about unfair competition and are starting to apply pressure on the government to restrict imports, whether made by foreign firms or United States firms that have located abroad, the Journal said.