Minnesota firms exported $20 billion worth of manufactured, agricultural and mining products last year, according to the state Department of Employment and Economic Development. That's down 7 percent from 2014's record. It's also lower than it could be if tariffs were lowered globally as a result of free-trade agreements like the Trans-Pacific Partnership (TPP), the 12-nation Pacific-rim pact that Congress is considering, and the Transatlantic Trade and Investment Partnership (T-TIP), the U.S.-European Union pact that the Obama administration is negotiating.

Despite the global benefits from reducing or eliminating tariffs — taxes, really — free trade has taken a beating in the presidential campaign. Republican front-runner Donald Trump rails against TPP and T-TIP, and even against NAFTA, the North American Free Trade Agreement that was signed over two decades ago. Trump takes his criticism a step further by threatening to slap big tariffs on Mexican and Chinese goods, which would likely spark a trade war that could dramatically destabilize an already-fragile global economy.

Democratic front-runner Hillary Clinton hasn't been as hotheaded as Trump. But facing a fierce primary challenge from anti-trade Bernie Sanders, Clinton has backed away from TPP despite publicly advocating for it at least 45 times when she was secretary of state.

She had good reason to tout the TPP: The diplomatic link to free trade is strong. Asian nations that are party to the agreement look at it as a real, not rhetorical, demonstration of President Obama's "pivot" to Asia, as well as a tool to counter China's increasing regional hegemony.

"We're one [TPP] vote away from either cementing our leadership role in the Asia-Pacific [region] and the global trading system, or ceding it to others," U.S. Trade Representative Michael Froman told the Star Tribune Editorial Board. Froman was in Minneapolis this month to accept the Bill Frenzel Champion of Free Trade Award from the Economic Club of Minnesota. He added that Minnesota — with its highly educated workforce, diverse economy and other assets — is "one of the states that stands to benefit most from this agreement."

That's also the view of Carla Hills, who was U.S. trade representative during the George H.W. Bush administration. Hills, a former Champion of Free Trade Award recipient, told an editorial writer that "all states will benefit, but Minnesota could really smile if this agreement goes through."

But the TPP is not going to win congressional approval unless U.S. employers deploy a concerted effort to counter the campaign trail rhetoric and convince Capitol Hill leaders that rejecting free-trade agreements won't stop globalization. In fact, the rest of the world is embracing free-trade agreements, which threatens to put the U.S. at a distinct disadvantage if it falls further behind.

U.S. leadership is essential in a rules-based trading system. No nation can push harder on labor, environmental, intellectual property and other trade standards. No trade agreement is perfect. There will be disruptions to industries and individuals. But these disruptions are occurring anyway, so it's best for the U.S. to mitigate them through the most favorable terms possible, as well as have robust worker retraining programs.

At a time of bipartisan concern over America's role in a rapidly changing world, it would be a long-lasting mistake to allow other nations, especially geopolitical rivals, to write the rules.

Rejecting TPP "would have a disastrous effect on our leadership. I can't imagine another government wanting to sit down and negotiate with us in the future," Hills said. "I don't know how [the U.S.] would dig out of the hole quickly."

Instead, the United States should be building strong trade relationships that expand exports and strengthen the economy.