From the News Tribune:

Tacoma, other West Coast ports face challenges: Competiton from north, south of U.S. borders

While the terminal operators in Mexico and Canada talk about serving their national markets, both Prince Rupert and Lazaro Cardenas have a common attribute that could make them strong competitors for U.S. business. Both ports are connected to U.S. population centers by relatively uncongested rail lines. The Canadian connection is via CN,
which owns a U.S. rail network as well as one in Canada. The Mexican connection is owned by the Kansas City Southern Railroad.

The Canadian and Mexican ports say they have some natural advantages that in some cases give them an edge in the container business.

American ports say they’re willing to compete with foreign ports based on natural attributes or other business factors, but they are trying to erase one cost advantage that they say Congress has unintentionally given those foreign ports.

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