Caught between the anti-globalist tirades of their presidential standard bearer and their state’s close trade ties with Mexico, Texas congressional Republicans are straddling a tricky political line when it comes to talk of renegotiating the North American Free Trade Agreement.

Republican nominee Donald Trump called NAFTA a “disaster” and backed renegotiating the pact in a policy speech in Detroit on Monday. Barring a better deal, he said, the United States should withdraw from the 22-year-old agreement that lowered trade barriers between the United States, Mexico and Canada.

Texas grassroots conservatives also want to abandon the deal. The Republican Party of Texas’ 2016 platform demands “immediate withdrawal from the North American Free Trade Agreement.”

But when The Texas Tribune reached out to each of the 27 Republican members of the Texas congressional delegation, not one joined in Trump’s call for renegotiating the treaty. None agreed to be interviewed, three responded with written statements and the others either did not respond or declined to comment.

“NAFTA is responsible for increasing trade between Texas and Mexico by almost 110 percent since 2004,” Rep. Will Hurd, R-San Antonio, said in a statement.

“Texas leads the nation in exports and benefits from international agreements that put Texans’ goods and services in front of more customers,” said Rep. Lamar Smith, R-San Antonio, who voted to ratify NAFTA in 1993.

In 1991, the year before President George H. W. Bush signed on to the terms of NAFTA, Texas exported $15.5 billion in goods to Mexico, according to the Texas Center’s Institute for International Trade. By 2015, that had increased sixfold. Last year, Texas’ export industry employed 1.1 million people — the most in the country, according to the U.S. Department of Commerce.

“NAFTA is not a dirty word in Texas,” U.S. Senate Majority Whip John Cornyn said in a March interview with the Brookings Institute.

Texas GOP public opinion on international trade deals has nonetheless soured. While no recent Texas polls have tracked NAFTA’s popularity specifically, a June 2016 poll conducted by the University of Texas at Austin’s Texas Policy Project showed 51 percent of state Republicans view trade agreements unfavorably, compared with just 17 percent who support them.

Scott Lincicome, an adjunct scholar at the Cato Institute, said public opinion of trade deals is often subject to “blind partisanship.”

Some Texas Republicans may dislike NAFTA in part because it was ratified when Democratic nominee Hillary Clinton’s husband was president, said Republican Party of Texas communications director Michael Joyce.

Clinton was also secretary of state during early negotiations of the pending Trans-Pacific Partnership.

Even Texas’ NAFTA detractors say the state has seen an economic boost from the deal’s reduced trade barriers.

U.S. Rep. Gene Green, D-Houston, who voted against NAFTA’s ratification, said, “I think NAFTA’s benefited the state as whole, but it hasn’t necessarily benefited my district.” Green added that if NAFTA were up for a vote today, he would not vote for it.

U.S. Rep. Beto O’Rourke, D-El Paso, said his region was “devastated” by NAFTA initially, with thousands of manufacturing jobs moving just across the border “almost overnight.” Eventually, though, El Paso adapted to the new economic reality, regaining many of the jobs originally lost, he said.

“If you’re just looking at the net impact, NAFTA was positive,” he said.

Trump’s campaign did not respond to multiple requests for comment, but Trump has suggested that he would renegotiate NAFTA by creating tariffs on certain goods to help protect U.S. manufacturers from foreign competition.

Tim Wise, director of the research and policy program at Tufts University’s Global Development and Environment Institute, has long criticized NAFTA’s lax environmental and labor standards. Like Trump, he would like to see NAFTA renegotiated. But he called Trump’s likely reform plan “absurd.”

“The idea that the U.S. could bully Mexico into accepting whatever trade protection Trump wants to impose without giving anything in return is not the way trade negotiations work,” he said.

Lincicome, a NAFTA supporter, noted that the tariffs Trump may favor are subject to congressional approval. But if Trump were to pull out of the deal, he said, many Texans, particularly poorer consumers and workers in the all-important energy sector, would feel a “devastating” economic backlash.

No Texas congressional Republicans addressed the possibility of a NAFTA opt-out.

In 2008, then-Senators Barack Obama and Hillary Clinton both said the next president should use an opt-out as leverage to renegotiate the deal’s labor and environmental standards.

President George W. Bush, a former governor of Texas, defended NAFTA then, saying, “now is not the time to renegotiate NAFTA or walk away from NAFTA.”

A campaign spokeswoman would not specify which aspects of NAFTA Clinton would now like to see changed or whether Clinton would opt out if those standards are not met.

Many NAFTA critics, including Green and Wise, attribute some of America’s immigration challenges to Mexican workers’ inability to prosper under NAFTA’s poorly enforced labor standards.

Clinton has said she does not support the Trans-Pacific Partnership, which would create stricter enforcement mechanisms for labor and environmental standards in NAFTA countries.

Trump has also not specified the reforms to NAFTA he would like to see. Asked in a July 26 Detroit News interview about renegotiation specifics, he assured he wants to change “many, many things.”

Rachel Wellhausen, an assistant professor of government at UT-Austin, said a potential renegotiation of NAFTA may not be as impactful to the larger economic picture as our politics might suggest.

“I would want the political rhetoric to be about job creation in the face of global competition and technology change,” she said. “It’s very unclear what renegotiating NAFTA would do, especially in an economy in which jobs are being lost to technology.”

Disclosure: The University of Texas at Austin has been a financial supporter of The Texas Tribune. A complete list of Tribune donors and sponsors can be viewed here.