President Donald Trump’s plan to double tariffs on foreign steel and aluminum — from 25% to 50% — could have sweeping effects on projects across Maryland, most notably the construction of the new Francis Scott Key Bridge. Trump announced on his Truth Social platform that the tariff hikes would take effect Wednesday and inject a “big jolt” into the domestic steel industry.

“These tariffs will further secure the steel industry in the U.S.,” he said during a visit to a U.S. Steel plant near Pittsburgh on Friday, where he also discussed Japan-based Nippon Steel’s potential investment in the company.

The office of Maryland Gov. Wes Moore pushed back on the proposal, saying the tariffs will hurt Maryland workers and families to “score political points.”

“The Trump-Vance Administration continues to unleash chaos across our state and around the country with these reckless blanket tariffs which will raise costs and will effectively be the largest tax hike in American history,” Gov. Moore’s spokesman Carter Elliott IV said in a statement to The Baltimore Sun. “These tariffs and the ensuing trade war they will cause, will lead to more inflation and push the American economy into recession.”

Steel prices have risen 16% since Trump became president in mid-January, according to the government’s Producer Price Index. Experts warn that even higher steel prices could threaten key infrastructure and manufacturing projects.

“I think this is definitely a concerning dynamic,” said Gabriel Mathy, associate professor of economics and fellow of American University’s Institute for Macroeconomic Policy and Analysis. “Steel is an important input into many American projects, including the Francis Scott Key Bridge. While steel is one manufacturing industry in the U.S., it’s more important as an input to other manufacturing and construction projects.

“To boost domestic projects in Maryland, like the Francis Scott Key Bridge, we should be trying to lower tariffs on steel, rather than raising them.”

Construction of the new Key Bridge is expected to begin in the early fall with an estimated cost between $1.7 billion and $1.9 billion. The new bridge is projected to be completed by October 2028.

Officials with the Maryland Department of Transportation deferred to Moore for a comment Saturday.

Daraius Irani, a Towson University economist and vice president of strategic partnerships and applied research, said the initial impact of the potential tariffs remains unclear. Some construction firms have an existing steel inventory, but projects that have not yet broken ground, such as building the new Key Bridge, could be affected.

The Associated Press contributed to this article. Have a news tip? Contact Todd Karpovich at tkarpovich@baltsun.com or on X as @ToddKarpovich.