FILE- In this Jan. 30, 2018, file photo, a container ship waits to be unloaded at the Port of Oakland in Oakland, Calif. The U.S. economy expanded at a solid 3.4 percent annual rate in the third quarter, slightly slower than the previous estimate as consumer spending and exports were revised lower. The economy is expected to slow further in the current quarter. The Commerce Department said Friday, Dec. 21, 2018, that growth in the gross domestic product, the economy’s total output of goods and services, was revised down from an earlier estimate of 3.5 percent. (AP Photo/Ben Margot, File)
WASHINGTON — The U.S. economy has turned in a stellar performance this year. But mounting problems, from trade tensions to jittery financial markets and political gridlock in Washington, are expected to sharply slow growth in 2019.