A Republican senator said Wednesday that claims that trade protectionism would restore the social and economic fabric of America’s past are “cruel” and untrue.

“If protectionism could bring back neighborhoods and nuclear families and lifelong employment, it would be well worth discussing. A lot of people would reasonably embrace that against some of the benefits of free trade,” said Sen. Ben Sasse, R-Neb. “The problem is, none of that is going to happen. It is fundamentally cruel to lie to people and say, ‘By government policy, we are going to make your communities stable again.’”

Sasse spoke at a trade forum sponsored by the Washington Examiner and held at The Heritage Foundation, where he criticized President Donald Trump’s policy of promoting tariffs and defended the North American Free Trade Agreement, which the Trump administration is renegotiating.

Sen. Joe Manchin, D-W.Va., who also spoke at the forum, was more on board with Trump’s trade policies, but urged an even more aggressive stance.

Trump, a Republican, has taken stances often at odds with his party on trade issues in seeking to renegotiate NAFTA and in imposing tariffs on steel and aluminum imports.

As if to underscore the point, in remarks in Washington on Tuesday night, Trump referenced support for his trade stance from across the aisle—that of Sen. Bernie Sanders of Vermont, an independent who caucuses with Democrats.

“We got a lot of Bernie Sanders [voters] voting for us. Can you believe it? Mostly people that didn’t like getting ripped off on trade—Bernie Sanders voters. He was right about that. But he wasn’t able to do anything about it,” Trump said at an event sponsored by the Susan B. Anthony List, a pro-life group.

He later added, “And we are renegotiating trade deals to bring jobs and wealth back home to America, where they and it belongs, working hard on the trade deals.”

Sasse, who represents one of the largest agricultural-exports states in the country, said Nebraska went from being about 70 percent supportive of free trade when he was first elected in 2014 to being 70 percent against it today.

Sasse argued that technology and automation have had more to do with the diminishing number of manufacturing jobs than trade deals do.

In 1900, he said, 41 percent of the U.S. labor market was involved in agricultural production. Today, it’s less than 2 percent. In the mid-1950s, almost one-third of the American labor market worked in factories. Today, that figure is 7 percent, the Nebraska lawmaker added. Yet, the United States has more total output.

In a question-and-answer format with the Washington Examiner’s Tim Carney, Sasse conceded that China is engaged in unfair trade practices, but contends the best way to combat that is to approve the Trans-Pacific Partnership, a trade deal among 12 countries that President Barack Obama couldn’t push through.

“The single best thing we could do to push back on Chinese bad behavior, and there is lots of it, would be leading TPP,” Sasse said. “If the U.S. were leading a whole bunch of other nations in the Pacific that believed in the rule of law, believed in free markets, believed in transparency, believed in human rights, believed in open sea lanes, that’s the single worst thing that can happen to China.”

In defending NAFTA, Sasse seemed to take a shot at Trump’s claims of business acumen.

“Recently, someone at the top of the executive branch used the phrase, ‘NAFTA is the single worst deal in the history of the world, either political or economical [sic].’ That’s just nuts,” Sasse said. “At the end of the day, NAFTA has been unbelievably good for the U.S. and for Mexico and for Canada. Trade deals and real estate deals are not the same.”

Sasse emphasized several times that trade deals are “win-win” for all countries, “not a zero-sum game.”

Manchin disagreed, however, calling out what he regards as problems with NAFTA, and seeking more bilateral agreements, which have been a hallmark policy of the Trump administration.

“I believe we should have an agreement with Mexico, and we should have another with Canada,” the West Virginia lawmaker said. “To go 20 years or more without having a review is unbelievable. I also believe all trade agreements should have a five-year sunset review.”

Using a line similar to one used by Trump, Manchin said, “I’m open to free trading, as long as there is fair trading with it.”

However, he said there seems to be internal struggle on trade issues at the White House.

“The undecidedness right now, and the administration’s tugging and pulling at each other, is causing inaction, and inaction is causing us a lot of consternation in the marketplace,” said Manchin.

Carney asked whether that could be part of Trump’s flexible-dealmaker approach to trade.

“Not if your rhetoric for the last year [is] ‘We got screwed. These are the horrible trade deals,’” Manchin responded. “A lot of people bought into that. We got screwed, and they were horrible trade deals. Fix them. I know a lot of his staff is pushing back.”

Tariffs are not the answer for the Trump administration’s goal of reviving manufacturing, argued Tori K. Whiting, a trade economist with The Heritage Foundation, who spoke at another panel discussion as part of the event. She said she has talked to manufacturers facing tariff-induced higher prices and are looking at possible layoffs as a consequence.

“These are companies that use steel and aluminum. They are really hurting,” Whiting said. “Tax reform was supposed to help these companies. Deregulation was supposed to help these companies. But if they can’t get the products they need at good prices, at prices that are buyable for them, they can’t do business.”