Every president since World War II has pursued a policy of expanding free trade. But in the 2016 presidential election, free trade has been an all-purpose villain.
Republican nominee Donald Trump has threatened to impose stiff tariffs on major trading partners such as China and Mexico, while Democratic runner-up Bernie Sanders rode an anti-free-trade message during his unexpected insurgency. Even Hillary Clinton, who supported free trade while serving as secretary of state, softened her position under pressure to defeat Sanders.
Further down the ballot, candidates have gotten the message: Today, it's rare to find politicians openly supporting free trade on the campaign trail.
"I know I have seen one positive ad about trade this year, but I can't find it," said Jennifer Duffy, who handicaps Senate and gubernatorial races for the Cook Political Report. "I remember it because it stuck out in a sea of anti-trade ads."
Duffy said that incumbents from the GOP -- the party that has been the primary supporters for free trade legislation in recent years -- have been "spooked by voters' reaction on trade this cycle. Wherever trade is playing this cycle, it is much more about opposition to trade agreements than about the virtues of trade."
The team of political analysts at Larry Sabato's Crystal Ball at the University of Virginia came to the same conclusion.
"We honestly can't think of anyone" who has articulated a pro-free-trade campaign message in 2016, said Kyle Kondik, the website's managing editor. "Free trade is an easy scapegoat for economic problems, and it's true that the benefits of free trade have been unevenly felt."
Even free-trade advocates have a hard time pointing to candidates this year who are running on their support of trade. When asked for examples of state-level politicians who have made support of free trade a key issue this year, several groups -- including the U.S. Chamber of Commerce and the Business Roundtable -- didn't have much to say.
Meanwhile, international trade has become a significant share of the economy.
Trade and the U.S. Economy
Federal estimates showed that 11.6 million U.S. jobs depended on trade in 2014. In 2015, the United States exported more than $2.3 trillion in goods and services. In all, trade accounted for 28 percent of the United States' gross domestic product -- up from 9 percent in 1960, which was before a string of key trade agreements took effect.
While U.S. exports in 2015 were exceeded by $2.8 trillion in imports -- producing a roughly $500 billion trade deficit -- imports themselves support jobs in the United States. And the lower prices from imported products enable Americans to enjoy a better standard of living than they would otherwise.
But don't expect candidates to mention these talking points this year.
"Free trade has always been a hard sell, even to many of those who benefit from it," said Tom Baxter, a veteran political reporter in Georgia.
It's also become increasingly common for Democrats to criticize free-trade deals. In 1993, 102 Democrats supported the North American Free Trade Agreement (NAFTA), according to the Wall Street Journal. Twelve years later, just 15 Democrats backed a free-trade deal with Central American nations.
What's different about this year is the backtracking by Republicans.
'That Scares Republicans'
This has been clearest in Senate races. As The New York Times recently noted, Republican Senate incumbents in Illinois, Missouri, Ohio, Pennsylvania and Wisconsin have been forced onto the defensive by Democratic challengers criticizing their past support for free trade.
Duffy of the Cook Political Report pointed to a recent ad from the Democrat-aligned Senate Majority PAC that attacked Republican Sen. Patrick Toomey of Pennsylvania. Toomey voted last year to give President Obama trade negotiating authority for the Trans-Pacific Partnership (TPP), a trade agreement with several Asian nations. (As his re-election campaign heated up this year, Toomey came out against the TPP deal itself.)
"Millionaire Pat Toomey," the ad's narrator said. "In Washington, Toomey's voted to protect tax breaks for companies that ship our jobs overseas. And Toomey's voted for seven separate trade deals that crippled our economy. Toomey even voted for special trade status with China. Tax breaks for outsourcing jobs. A special trade deal with China. Pat Toomey: in Washington, he hasn't been standing up for us."
"It's the linkage between jobs moving overseas and trade that scares Republicans," said Duffy. "Even though the two aren't necessarily related, voters are convinced that they are."
In Ohio, Republicans have been split over the issue.
Republicans in the state's congressional delegation were all over the map on approving trade promotion authority, according to Thomas C. Sutton, a political scientist at Baldwin Wallace University in Berea, Ohio. The incumbent Republican senator, Rob Portman, has softened his support for trade agreements as he seeks a new term in 2016.
As for the state's governor, Republican John Kasich, Sutton said "he's been consistent in supporting free trade as beneficial to Ohio, particularly for farming and the services and technology sectors." But even though Kasich sees benefits for manufacturing from free trade, "he does not promote this as heavily."
In other Midwestern states, few Republicans have gone out on a limb.
In a competitive congressional contest in northern Minnesota, for example, both candidates --incumbent Rick Nolan, a Democrat, and his GOP challenger, Stewart Mills -- "are asserting their opposition to trade arrangements that have cost the district jobs," said Carleton College political scientist Steve Schier. "Up there, the campaign talk is very much anti-trade."
But not every part of the country is seeing such anti-trade fervor.
Trade Isn't Taboo Everywhere
In Massachusetts, for instance, which Governing recently rated as having the strongest overall economy in the nation, trade is generally seen as a good thing.
"The dominant view is that free trade is vitally important to the state," said Tufts University political scientist Jeffrey Berry. "There's very little manufacturing here, while the high tech, biotech and engineering firms that are the engine of the state's economy value foreign trade."
Another region where free trade is either welcomed, or at least tolerated, is the South.
In Texas, "free trade continues to be widely supported by most Texas Republican elected officials, as well as by a significant number of Texas Democrats," said Rice University political scientist Mark P. Jones.
Vocal supporters in Texas, he said, include Gov. Greg Abbott, Sen. John Cornyn and Rep. Kevin Brady, all Republicans. Some Democrats are also supportive of free trade because NAFTA has bolstered many heavily Hispanic -- and heavily Democratic -- districts near the Rio Grande.
"By and large," said Jones, "there has been little backlash at the polls in either party against politicians who remain visibly and vocally supportive of free trade."
Other states in the South welcome free trade because they either lack labor unions (which usually rail against trade deals), have a big agricultural sector looking to sell its products abroad or have experienced a record of investment by foreign companies in manufacturing.
"Louisiana is a heavy trade state, and everyone is on board," said G. Pearson Cross, a University of Louisiana-Lafayette political scientist. "We haven't really sent jobs overseas because our industries -- agriculture, oil, fisheries -- are here and can't be moved. What Louisiana politicians want is more trade on fair terms, along the lines of, 'Let our rice compete with theirs.'"
For some Republican governors, their own longstanding support for free trade is running contrary to their backing for Trump.
In Florida, Republican Gov. Rick Scott -- a Trump backer -- has consistently touted free trade as a key to future economic growth.
"Florida is already a hub for trade in and out of Latin America and the Caribbean," and Scott has backed expanding trade with Japan and China, said Aubrey Jewett, a University of Central Florida political scientist.
Iowa Republican Gov. Terry Branstad, another longtime free-trade advocate, is also supporting Trump. But Branstad "has touted the close relationship he has with President Xi Jinping of China and how this benefits the Iowa economy," said Christopher Larimer, a University of Northern Iowa political scientist.
Sometimes the solution can be as simple as changing the rhetoric, said Douglas Irwin, a Dartmouth University economist and author of Free Trade Under Fire.
"In many southern states," he said, "politicians tout the benefits of 'foreign investment' but not 'free trade.'"