President Donald Trump is threatening extensive import tariffs on Chinese products, but two key political groups that have backed him from the beginning of his presidency aren't yet convinced the rhetoric will hurt Republican chances in the 2018 congressional elections, CNBC has learned.

Brian O. Walsh, the head of the nonprofit Trump advocacy group America First Policies and its sister political action committee, America First Action, told CNBC on Friday that there's a lack of polling data to suggest a trade war will hurt Republican efforts this year.

"I'm not concerned yet. The data that I've seen on trade and tariffs, at least nationally, is that it's complicated in different parts of the country. For some people it's a big deal, for others it's not," Walsh said. "We haven't really polled yet on that issue."

However, while America First Policies did not poll on the idea of a trade war, it did gather mixed results from voters regarding Trump's large-scale import tariffs on steel and aluminum.

In the group's most recent poll, from March, 45 percent of voters said they backed the tariffs, while 39 percent said they were against them. Of the respondents who said they opposed the move, 47 percent of that total noted they would not support the decision even if jobs were created.

The pro-Trump PAC, America First Action, has already tried to make an impact during the early stages of the 2018 campaign, but the results haven't been the best.

The group spent $1.7 million to take on Democrat Conor Lamb during the special congressional election for Pennsylvania's 18th District, according to the Center for Responsive Politics. Lamb narrowly edged his Trump-endorsed Republican opponent, Rick Saccone.

The PAC also tried to prevent Democrats from flipping the Alabama Senate seat vacated by Attorney General Jeff Sessions. The group spent $1 million in the state, but Democrat Doug Jones defeated Republican candidate Roy Moore, who was accused of sexually assaulting teenage girls. Trump endorsed Moore in the home stretch of the campaign after initially backing former state Attorney General Luther Strange during the GOP primary.

Beyond the public statements of support for the current administration, privately, the leaders of the organization have been meeting with the president.

Last month Trump was wined and dined at the home of powerful Washington, D.C., attorney C. Boyden Gray along with Dallas financier Roy Bailey, the national finance chairman for America First Action, and oil tycoon Harold Hamm, board member of America First Policies.

As the group shrugs off the president's saber-rattling over tariffs, Trump continues to push his administration toward the path of an all-out trade confrontation with China.

On Thursday, Trump ordered government officials to identify an additional $100 billion worth of tariffs. The next day the Chinese government said it was fully prepared to respond with a "fierce counter strike" of fresh trade measures if the United States follows through.

The move drew intense criticism from Republican lawmakers in the heartland, but the president didn't appear to be backing down from critics.

On Friday, he tweeted a broadside at the World Trade Organization.

"China, which is a great economic power, is considered a Developing Nation within the World Trade Organization," Trump said. "They therefore get tremendous perks and advantages, especially over the U.S. ... The WTO is unfair to U.S.," he added.

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The markets have also been on a roller-coaster ride. The Dow Jones industrial average fell more than 400 points Friday morning as investors continued to fear a trade war.

— CNBC's Christina Wilkie contributed to this report.