President Donald Trump may tie his decision on steel and aluminum tariffs to a rally in southwestern Pennsylvania, currently in the works for March 10, according to three people with knowledge of the event.

The announcement on tariffs — closely watched by trading partners and global investors — could be made in the lead-up to the event, these people told CNBC.



The rally is tentatively scheduled for three days before a special election in Pennsylvania's 18th District to fill the seat of Republican Rep. Tim Murphy, who resigned last October after it was revealed the pro-life Murphy suggested his mistress seek an abortion.

Trump's potential visit to the district to talk up a labor-friendly policy to restore American steel and aluminum production would be one way to help Republican candidate Rick Saccone solidify his support.

"Rick is very pleased to have the President's support and would welcome him to the 18th," said Saccone's spokesman, Patrick McCann. McCann said Saccone would engage with voters on tax cuts and national security and would support steel and aluminum tariffs if "other countries aren't playing by the rules."

The race to claim the seat, which Murphy had held since 2003, is heating up. The Democratic challenger, Conor Lamb, is trying to appeal to blue-collar sensibilities in an attempt to flip people who voted for Trump in 2016.

Saccone had held a 12-point lead over Lamb in January, but it has been cut by at least half, according to mid-February polls by Gravis Marketing and Monmouth University.

"There is nothing currently on the schedule for the president to go to Pennsylvania," according to White House deputy press secretary Lindsay Walters.

One wild card in the scenario: Whether policy differences among Cabinet members can be reconciled before March 10, the prospect of which was doubted by two White House officials.

The Commerce Department has offered Trump a menu of options — global tariffs, targeted tariffs and global quotas — to shore up American steel and aluminum production. A senior administration official called the final decision a "moving target," despite Trump's backing of global tariffs. A memo from the Department of Defense raised concerns "about the negative impact on our key allies" but suggested targeted tariffs would do the least harm.

The White House trade pendulum appears to be swinging back toward the protectionist policies Trump praised on the campaign trail that have been diluted or shelved during his presidency. Recent evidence of this trend: The potential ascension of well-known trade hawk Peter Navarro, countered by the removal of staff secretary Rob Porter, who resigned earlier this month after two ex-wives accused him of domestic abuse. Porter was not often mentioned as a player on trade policy, but he was an influential force nonetheless.

"Rob Porter controlled the information flow, and what he was good at was slowing things down when he needed to," said a former White House official with knowledge of the discussions.

Porter and Trump's top economic advisor, Gary Cohn, bought time, this official said, to push beyond the White House's self-imposed deadlines on trade probes. While the steel and aluminum investigation carried a deadline of 270 days by law, "the initial goal inside the White House was to have Commerce weigh in within 60 days."

The pursuit of tariffs isn't uniformly popular across Pennsylvania. Republican Sen. Pat Toomey has urged the president to tread carefully where tariffs are concerned.

"I would just urge us to go very, very cautiously here," Toomey told Trump and White House officials Feb. 13. "Invoking national security when I think it's really hard to make that case invites retaliation that'll be problematic for us."

The issue isn't one drawn along clear party lines, either: Sen. Rob Portman, R-Ohio, who served as U.S. trade representative under George W. Bush, sent a letter to Trump co-signed by four Democratic colleagues urging action on tariffs and arguing that past negotiations were ineffective.

"We believe a long-term enforcement approach is the only way to obtain the relief the American steel industry and its steelworkers need," the letter said.

Trump has until April 11 to finalize his decision on steel and April 19 to finalize his decision on aluminum. Defense Secretary James Mattis, in his memo last week, suggested a delay on aluminum because the threat of action was enough.