Here's how a Trump trade war would hit your state

If your state exports goods and services to China or Mexico, you may want to pay closer attention to the presidential candidates' positions on global trade.

After decades of liberalized trade deals and lower tariffs helped boost import and export traffic around the world, the engine of global trade is slowing. That's one reason the overall pace of the global economic growth remains relatively weak.

That wave of globalization has also produced a backlash — from American voters who've lost their jobs to British voters who go to the polls Thursday to decide whether to reclaim their independence from the European Union.

In the United States, anti-free-trade sentiment has propelled real estate developer Donald Trump to the front of the GOP pack of presidential candidates, including a pledge to reverse the 1994 North American Free Trade Agreement with Canada and Mexico, the two top U.S. trade partners.

"We will either renegotiate it or we will break it," Trump said last fall, calling it "a disaster. Every agreement has an end. Every agreement has to be fair."

Trump has also vowed to raise tariffs on Mexico and China. Those higher tariffs would almost certainly cut into U.S. exports, which represent about $2 trillion, or roughly one-eighth of the nation's gross domestic product.

But that impact varies widely from one U.S. state to another, with West Coast states more heavily reliant on Chinese markets and border states seeing the biggest demand from Mexico.

China represents the third-largest U.S. export market, after Canada and Mexico, accounting for nearly $120 billion worth of goods last year. Overall, that represents less than 8 percent of U.S. exports — or less than 1 percent of total gross domestic product.

But the Chinese market is a much bigger deal for a handful of West Coast states.

Among the most dependent: Washington, which sold roughly 20 percent of its exports to China last year, or nearly $19 billion worth of goods. Airplanes, the state's largest export by far, made up the bulk of the state's sales to China.

California exports some $16 billion to mainland China, with computers and electronics accounting for more than a quarter of the total. Texas was the third-largest exporter to China, with more than $11 billion worth of products that included chemicals, computers and machinery.

Alaska, which exports a smaller volume of goods, sends $1.5 billion worth of its exports — a quarter of the total — to China. Roughly half of that consists of seafood.

U.S. farm states are also big exporters to China, which is the biggest single market for American agricultural products. Some 20 percent of all U.S. farm exports are sold to China, which bought $30 billion worth of food and other farm products in fiscal year 2014, including soybeans, distillers' grains, hides and skins, tree nuts, coarse grains, cotton and beef, according to the U.S. Department of Agriculture.

Mexico — the second-largest U.S. market — bought $236 billion, or nearly 16 percent of last year's total sale of goods and services overseas. Those sales supported an estimated 1.1 million jobs in 2014, according to the latest data available from the Department of Commerce.

The top Texas products sold south of the border include computers ($95 billion last year), transportation equipment ($24 billion) and oil and chemicals ($23 billion).

Other border states also depend heavily on Mexico as a buyer of exports. New Mexico sends 45 percent of its exports south of the border.

But even as the pace of global trade slows, so does support for a pair of deals designed to revive it.

After years of talks and months of high-profile meetings and speeches to win approval, the White House so far has failed to convince Congress — or voters — that lowering trade barriers with Europe and Asia will help boost the growth of the U.S. economy.

The future of trade deals

Earlier this year, President Obama met with German Chancellor Angela Merkel to try to win backing for the so-called Trans-Atlantic Trade and Investment Partnership, aimed at boosting trade between the U.S. and European economies. The United States is Germany's biggest trading partner.

Supporters of the sweeping deal being negotiated with 28 European Union countries say it could add $100 billion a year to U.S. exports.

The Obama administration's Asia-Pacific trade deal has also gotten a chilly reception from the Democratic presumptive nominee Hillary Clinton.

The former Secretary of State, who initially supported the idea of expanding Asia-Pacific trade, has come out against the proposed Trans-Pacific Partnership, saying she doesn't like the terms. (Clinton hasn't taken a position on the ongoing talks to reach a deal with Europe.)

The White House has acknowledged it faces an uphill battle selling trade deals to a skeptical public.

"I think that we have to do a better job … to counteract voices that are distorting the reality of trade agreements," U.S. Commerce Secretary Penny Pritzker told CNBC earlier this year.

But with little support from the presidential candidates, the deal's future is not looking bright.

Obama has conceded as much in his efforts to win support.

"If we don't complete negotiations this year, then upcoming political transitions in the United States and Europe could mean this agreement won't be finished for quite some time," Obama said at a news conference earlier this year.

— By CNBC's John Schoen. Follow him on Twitter @johnwschoen or email him.