Decrying global trade deals has become a rhetorical mainstay of the 2016 campaign, and Democratic U.S. Senate candidate Russ Feingold is part of that chorus — while his opponent, Republican Sen. Ron Johnson, has stayed mum.

Presumptive Republican presidential nominee Donald Trump and Democrat Bernie Sanders have elevated the issue by unreservedly bashing free trade deals such as the proposed Trans-Pacific Partnership. Trump has said “we are killing ourselves with trade pacts” and described free trade with China as “stupid trade.”

Trump’s rhetoric has created a dilemma for Johnson, who co-founded a manufacturing business and generally favors free trade. But Johnson has not declared his stance on the Trans-Pacific Partnership, or TPP — saying he’s still reviewing the deal seven months after it became public. The deal would forge trade ties between the U.S. and 11 nations on the Pacific Rim.

“Ron is doing the hard work of reviewing the final version of this deal as he talks with Wisconsin families, farmers, small businesses and all others concerned,” Johnson spokesman Brian Reisinger said in a statement. The Wisconsin State Journal asked to interview Johnson for this story but he declined.

Meanwhile, Feingold, D-Middleton, who fought trade deals throughout his lengthy political career, in this campaign has highlighted his opposition to the latest potential deal, in TPP.

Wisconsin business leaders say rejecting TPP would eliminate opportunities for businesses here that export their wares abroad. Global trade supports nearly one-fourth of all Wisconsin jobs, and the state’s companies and farmers exported more than $23 billion in goods and services in 2014, according to Wisconsin Manufacturers & Commerce.

Worse still, says WMC CEO Kurt Bauer, is Trump’s call for steep tariffs on imports from China and Mexico. Trump has proposed a 45 percent tariff on Chinese goods coming into the U.S. and a 35 percent tariff on some Mexican imports, such as cars.

“Who the hell cares about a trade war?” Trump proclaimed at a rally last month.

Bauer, whose organization aligns with Republicans on most issues, said Wisconsinites should care — in part because the state’s economy relies heavily on manufacturing exports.

“We are particularly vulnerable in Wisconsin to a trade war,” Bauer said.

Asked if he’s troubled to hear the presumptive GOP nominee offering such proposals, Bauer said: “It troubles me, period. I don’t think it matters if it’s coming from a Republican or a Democrat.”

Haven’t reviewed Trump’s proposal, Johnson says

When asked if Johnson supports Trump’s call for tariffs on Chinese and Mexican goods, Reisinger said the senator “has not reviewed these specific proposals.”

Feingold told the Wisconsin State Journal that such tariffs are “not a good idea.”

Trump’s anti-trade stance bucks the majority of Republicans and conservatives, including U.S. House Speaker Paul Ryan of Janesville, who generally view free trade favorably.

Democrats traditionally were the party divided on trade. Former President Bill Clinton was the champion of the North American Free Trade Agreement, enacted in 1994 and the first in a series of deals with Latin American countries, South Korea and others. Most recently, President Barack Obama’s administration negotiated TPP.

But TPP has elicited an eclectic coalition of foes that include organized labor on the left and a Trump-led “America First” coalition on the right.

Proponents of TPP say it’s largely about boosting U.S. influence in fast-growing parts of East Asia. By strengthening trade ties with Japan, Vietnam, Malaysia, Singapore and other nations, they say the deal could stave off rising Chinese influence in the region.

The proposed deal outlines plans to remove or lower tariffs on a range of products, to resolve international investor disputes and includes protections for intellectual property such as copyrights and patents. Labor provisions of the deal would require participating countries to allow workers to join unions and collectively bargain, do away with child labor and forced labor and be free from employment discrimination.

Critics question the enforceability of the labor and discrimination provisions. They point to job losses that followed past trade deals as signs that, however they’re initially billed, they end up hurting U.S. workers.

U.S. Sen. Tammy Baldwin, D-Madison, and Rep. Mark Pocan, D-Cross Plains, are against TPP, while Rep. Ron Kind, D-La Crosse, has joined Obama’s administration in pushing for it. Presumptive Democratic presidential nominee Hillary Clinton has come out against TPP after praising it while she was secretary of state.

Feingold calls it a badtrade-off for Wisconsin

Last year, Johnson voted for a measure enabling the White House to negotiate trade deals and submit them for congressional approval without changes. The vote came before all of the deal was made public, but nonetheless was viewed by many as a test vote for its contents.

Feingold said he isn’t opposed in principle to all trade deals. But he said agreements adopted over the last quarter-century — starting with the North American Free Trade Agreement, or NAFTA, which he opposed as a newly elected senator in 1993 — haven’t served U.S. workers. Instead, Feingold contends they benefited corporate CEOs and shareholders by making it easier to move U.S. jobs abroad.

Feingold cites a figure that 75,000 Wisconsin jobs have been lost to overseas companies since NAFTA took effect. That’s based on the number of workers certified for Trade Adjustment Assistance, a federal program that aids workers displaced by outsourcing or imports.

Feingold conceded consumers may see benefits from free trade deals in the form of cheaper goods. But for Wisconsin as a whole, he said the net effect is destructive.

“If you compare paying a little bit less for a refrigerator or golf clubs to losing your livelihood, there’s really no comparison,” Feingold said.

Some experts outside the political sphere say it’s misguided to blame trade deals for the trend of outsourcing U.S. manufacturing jobs. Some say it instead is spurred by other trends such as automation and industrialization in developing countries such as China and Mexico.

Mark Copelovitch, a UW-Madison professor and expert on international trade, told the State Journal that most political critiques focus “almost exclusively on the costs of trade while ignoring the benefits.”

“The central issue with free trade is that it has large benefits for society as a whole but very large distributional costs (winners and losers),” Copelovitch said. The winners, Copelovitch said, include consumers who get cheaper goods. The losers include U.S. workers in industries such as clothing and furniture, which face competition from China and other points overseas.

‘Wall ourselves offfrom opportunities’

There are fresh signs that Trump’s anti-trade views are influencing the Republican rank-and-file.

One came from the latest Marquette Law School Poll, which showed a new development in Wisconsin public opinion on trade.

In what pollster Charles Franklin described as a reversal from past numbers, a larger share of Republican versus Democratic respondents to the poll said free trade deals have been bad for the U.S.

To Feingold, the shift in public opinion is a sign “the chickens have come home to roost for Republicans.”

“Their supporters have finally figured out: These guys just get in there, like Sen. Johnson, and vote to ship jobs overseas,” Feingold said.

Reisinger questioned Feingold’s motives on TPP, noting he went public with his opposition before the full deal was made public.

“He made a knee-jerk reaction based on incomplete information to score cheap political points,” Reisinger said.