TOPEKA — Kansas lawmakers, representing a heavily agricultural state, are defending free trade amid a presidential election race where trade is playing an outsize role and candidates question the value of open markets.

Presumptive Republican nominee Donald Trump and Democratic candidate Bernie Sanders both have questioned the wisdom of free trade, and Democratic frontrunner Hillary Clinton stands opposed to a recent trade agreement with Pacific Rim nations. With Republicans traditionally more open to trade, Trump’s skepticism has helped turn trade into one of the most prominent issue of the campaign.

Trump’s lock on the nomination also means Republicans are likely headed to a reckoning on trade, where the party will have to re-evaluate where it stands.

“America has always been a trading nation. Under the Trump administration, trade will flourish. However, for free trade to bring prosperity to America, it must also be fair trade. Our goal is not protectionism but accountability,” the Trump campaign says.

Federal legislators from Kansas indicate they remain committed to trade, though some suggest the need for better enforcement of international agreements.

“There are certain areas that don’t do well on trade. But for a Kansas wheat farmer, we export 52 percent of everything we grow — not just out of Kansas, but out of America. We don’t have the option of slamming the doors on trade, and we want to make sure we have a level playing field, and often in agriculture we don’t get it,” Rep. Tim Huelskamp said.

Trump has threatened a 45-percent tariff on Chinese goods. His campaign promises to fight Chinese currency manipulation by labeling the country a currency manipulator, which he argues will impose duties on artificially cheap Chinese products.

Sen. Jerry Moran said currency manipulation is a good example of how countries take advantage of trade deals with the U.S.

“We need to have a serious conversation about trade and trade agreements. I think in too many instances the folks who negotiate a trade agreement, they do a series of high-fives — ‘we’ve reached an agreement’ — and people are excited about the agreement, but then administrations look the other way when it comes to enforcing the terms of that agreement. And in way too many instances, other countries take advantage of those agreements,” Moran said.

Congress is grappling with the Trans-Pacific Partnership, a trade agreement made by President Barack Obama with 11 other nations. Known as the TPP, the agreement has yet to be ratified by Congress — an action not assured.

Trump, Sanders and Clinton all oppose the TPP. The agreement would lower tariffs in an effort to increase trade among the member nations. But opponents worry it will squeeze American workers while harming environmental protections.

Huelskamp said “within weeks” under the TPP, more Kansas exports would be headed to Japan. Sen. Pat Roberts said every trade agreement he has been involved with has been over-criticized.

The devil is in the details, Roberts said. Trade bills need presidential leadership, he argued, saying Obama hasn’t provided it.

“Unfortunately, this president, with all due respect, has not engaged the Congress about anything I can think of, other than the criticism, and you have to have presidential engagement and leadership on a trade bill or you’re just not going to get it done,” Roberts said.

Obama has struck back at Trump’s position on trade. Speaking in Indiana this past week, he criticized Trump’s trade position while not mentioning the candidate by name.

Obama said trade has helped America much more than it’s hurt the country.

“Exports helped lead us out of the recession,” Obama said. “Companies that export pay workers higher wages than folks who don’t export. And anybody who says that somehow shutting ourselves off from trade is going to bring jobs back, they’re just not telling the truth.”