If you knew nothing about American politics and were seeing the 2016 campaign for the first time, you might reasonably assume that American voters really dislike trade deals.
The Republican front-runner, after all, can't stop talking about the dangers of trade with China and all the problems existing trade deals have caused. And on the Democratic side, Bernie Sanders has constantly lambasted front-runner Hillary Clinton for her past support of trade pacts. Both get big applause when they campaign about the evils of trade deals — and notably, there's no candidate with a similarly energetic stump speech (that gets a similarly raucous reaction) for trade pacts.
And yet. Americans are feeling pretty positive about foreign trade these days. In addition, most mainstream economists think trade is (on balance) a good thing. But criticizing trade deals remains an effective stump topic. Here's what's going on behind the messy politics of trade:
Americans are pretty positive about trade
In the recent primary elections, Republicans and Democrats alike have been skeptical of free trade, at least from the standpoint of job creation. In both Ohio and Michigan — both of which are known for their manufacturing, an industry that many argue has been hit hard by trade deals — Republicans and Democrats had remarkably similar views on trade. A little more than half of people in both parties in both states said trade "takes away jobs." Meanwhile, only around one-third of people across the board said it creates jobs.
But as it turns out, Americans as a whole seem to feel pretty good about foreign trade. Gallup found in February (hat-tip to the Upshot's Justin Wolfers) that 58 percent of Americans see trade as more of an opportunity than a threat.
Interestingly, polls also show that Democrats right now are slightly more in favor of free trade than Republicans. In the early 2000s, Republicans were more likely to see trade as an opportunity than a threat, according to Gallup. But around 2011, Democrats surpassed them. Around 61 percent of Democrats saw trade as an opportunity as of 2015, compared to 51 percent of Republicans.
This bucks conventional wisdom that Republicans are more the party of free trade. (After all, big business interest groups, like the Chamber of Commerce, who support trade pacts, tend to support Republican politicians, while unions — major Democratic supporters — oppose many trade pacts). Indeed, both parties appear to be (moderately) the parties of free trade.
The bottom line, according to one public-opinion expert, is that Americans' views on trade may shift back and forth, but they never really get that extreme.
"Trade is never wildly popular, but sometimes it's less unpopular," said Karlyn Bowman, a senior fellow and public opinion analyst at the American Enterprise Institute, a right-leaning think tank in Washington, DC.
Economists are pretty well decided: trade is good
Many mainstream economists, meanwhile, are decided that free trade is (on the whole) a good thing.
In a 2012 survey of top economists, 85 percent agreed that the benefits of free trade are "much larger than any effects on employment." Only 5 percent were uncertain.
They also overwhelmingly agreed that Americans are far better off with NAFTA than if the pact hadn't been passed. Likewise, in a 2014 survey, more than 80 percent of economists agreed that past trade deals "have benefited most Americans."
The basic arguments economists often make for freer trade are simple: the ideas are that trade opens up more markets to U.S. exports, gives Americans more goods to choose from, and exchanges lower-paying jobs for higher-paying ones, as the Peterson Institute for International Economics' Gary Hufbauer recently explained to NPR.
But to paraphrase Harry Truman, there are no one-handed economists. In those surveys, the economists expressed plenty of reservations about trade: some stressed that these gains only come about in the long term, and moreover that it's important to recognize that there are losers from trade deals (like people whose jobs end up moving overseas).
Indeed, some recent studies have raised concerns that opening up trade with China has hurt American manufacturing.
It's true that a huge share of Americans will enjoy lower prices and more choice at the store — and that a smaller number might get new jobs because of a trade deal. But there are also people who will be much, much worse off if their factory job moves to another country. That effect won't hit many people, but it's still devastating for them.
What it all means: jobs and avocados
And that's where we get back to the campaign trail, where populist anti-trade-pact views and Americans' moderately-maybe-supportive opinions on trade meet.
There are a few big potential reasons why trade resonates on the campaign trail. One is that primary voters are different from general election voters; it's possible that the people coming out to vote in the nominating contests feel much more strongly about trade than the general population.
Another is that people like trade in theory but not when it comes down to specific deals. Pew found evidence of this in 2010: Americans liked the idea of trading with an array of foreign countries, but specific trade deals like NAFTA were really unpopular.
But there's a third, compelling possibility: it's easier to get fired up about the problems with trade deals than it is about their benefits.
"It's one of those many issues where people are pulled back and forth, where people who have lost jobs feel very strongly" — and understandably so, Bowman said. She added, "Even when you do see it — when you're getting a pair of shoes for a pretty good price — you don't necessarily link that to free trade."
One way of summing it up is that for most Americans, the benefits of a trade pact are subtle — lower prices and, say, greater avocado availability. But for the rarer people who, for example, see a factory close because of trade, the effects run much deeper and can even be life-altering.
And this works to the advantage of politicians who sincerely oppose these trade deals.
It's not just voters who have a complicated relationship with trade. Among Washington politicians, there also aren't a lot of neat partisan lines on trade. In pushing his Trans-Pacific Partnership, President Obama has met opposition from Democrats and Republicans alike.
Similarly, many politicians will often support one pact and then lambast another. Just eight years ago, Obama was hitting Clinton from the left on her past support of NAFTA. Now, he's promoting a trade deal amid bipartisan opposition. Likewise, Hillary Clinton was an advocate for TPP before she was against it.
Both Obama and Clinton say it's about the content of the TPP. The administration says the pact is a big improvement upon NAFTA. Clinton, meanwhile, says that TPP doesn't clear the "high bar" she has set for it.
But basic politics also can explain why politicians might support or oppose trade deals — some Republicans on the Hill simply might not want to hand the president a win on TPP, for example.
And politics can also explain why a politician from either party could be expected to like free trade a bit more once he or she gets into the Oval Office.
"[W]hen politicians become presidents, not everything is so simple or populist, and they become more amenable to rational arguments," said Barry Bosworth, senior fellow at the Brookings Institution, in an email. "Republican presidents are strongly influenced by business leaders and Democrats more by academic economists, but both groups are strong supporters of open trade in an increasingly globalized economy."