– Minnesota’s newest congressman, Republican Tom Emmer, spent February meeting personally with every other freshman Republican in the U.S. House of Representatives. He urged each of them to support trade promotion authority.

Minnesota’s longest-serving congressman, Democrat Collin Peterson, fields calls every week from members of President Obama’s Cabinet courting his support for trade promotion.

A furious back-channel lobbying effort roils Capitol Hill these days. Ultimately, it seeks to open international markets to U.S. multinational companies, including Minnesota-based 3M, Medtronic, St. Jude Medical, Ecolab and Cargill, through the 11-country Trans Pacific Partnership. But the fate of the nation’s most important trade deal since the North American Free Trade Agreement (NAFTA) rests with passage of trade promotion authority — legislation that allows the Senate and House to set objectives for trade deals, but only allows a yes-or-no vote and no amendments to specific agreements.

“It is impossible to negotiate a serious trade agreement without it,” said University of Minnesota trade expert Tim Kehoe, who advised the Mexican secretary of trade during NAFTA. “When you negotiate, you give up things to get things.”

Letting House and Senate members renegotiate those promises as part of the approval process, said Kehoe, inevitably leads to district-by-district and state-by-state nitpicking that dooms any deal.

And yet passage of trade promotion — one of the few issues where leaders of the Republican-controlled House and Senate side with the Democratic White House — appears anything but certain. A trade promotion authority bill has yet to be introduced in the House or Senate. Meanwhile, the window of opportunity for a major free-trade agreement closes a little more each day the country advances toward the 2016 presidential and congressional elections.

“The closer to the 2016 elections we get, politicians get more skittish,” explained Bryan Riley, senior trade policy analyst at the Heritage Foundation, a conservative think tank. “There are vocal aspects of both parties that don’t like trade promotion authority and have the ability to make people nervous.”

Nationally, the issue has driven a wedge between Republicans. It has caused many Democrats to fall out with Obama.

Minnesota’s U.S. senators, Amy Klobuchar and Al Franken, both Democrats, are not on board with trade promotion authority, which is popularly known as “fast track.”

“I am opposed to fast-track authority, because real congressional input is necessary to ensure that any trade deal will truly benefit Minnesota,” Franken said.

Klobuchar said she will look at any trade promotion bill to see “how it addresses important issues like intellectual property, currency manipulation, and transparency.”

The Minnesota House delegation split along party lines. Emmer and fellow Republicans Erik Paulsen and John Kline support a trade promotion bill that will provide a path to passage for the Trans Pacific Partnership agreement.

Paulsen, one of the House’s leading free-trade advocates, is part of a trade working group that has been scouring the Capitol trying to answer concerns of skeptical Republicans.

“We’re attacking the notion that we’re ceding Congress’ authority,” Paulsen said. “Trade promotion authority sets out clear negotiating objectives.”

Minnesota’s House Democrats Peterson, Tim Walz, Betty McCollum, Keith Ellison and Rick Nolan are either against trade promotion authority or unconvinced, putting them at odds with Obama.

Peterson wants assurances that the Trans Pacific Partnership — known as TPP — will increase exports for farmers in his rural district. Walz finds the secrecy of the negotiations off-putting. McCollum wants the ability to “amend harmful policies.”

Ellison, who just co-authored an anti-trade promotion op-ed in the Guardian, a British newspaper, offered a litany of complaints, including lost U.S. jobs, trade deficits, currency manipulation and lack of environmental protection. Usually one of Obama’s most vocal supporters, Ellison expressed frustration that the White House “is leaning hard on people to bring them around” to support trade promotion authority for TPP.

“For the life of me,” said Ellison, “I don’t understand how our president can say income inequality is the defining issue of our time and be for this.”

“Fast track” dates to 1974. The idea, said Kehoe, was to give negotiators parameters, but free them to strike the best deal they could.

Kline believes it is the way to go.

“You can’t get these deals done without trade promotion,” he contended. “We retain the right to reject any agreement at the end.”

Trade promotion was easier to pass four decades ago, most experts say. Today, issues like intellectual property rights complicate trade deals. Free trade has also become the proxy for debates on everything from American job creation to fair pay to human rights to environmental protection to executive power.

Multinational companies want free trade agreements and the trade promotion authority that enables them. Business and trade groups say 95 percent of the world’s consumers live outside the United States so the only way to let American businesses grow is to tap those foreign markets.

Federal filings show that Medtronic, St. Jude Medical, Ecolab and 3M all spent money lobbying on trade promotion authority in 2014.

“3M is supportive of passing trade promotion authority,” a company spokeswoman told the Star Tribune. “The expansion of free and fair trade is essential to grow the U.S. economy and American jobs.

Labor unions have traditionally opposed free trade agreements and the trade promotion, saying they cost American jobs and run down overall wages and benefits.

“If the Obama administration wants to do trade policy right, they should focus on transparency in the trade negotiations, putting human rights above corporate profits, and creating policy that reduces our trade deficit,” said Josh Wise, director of the Minnesota Fair Trade Coalition, a group of “over 80 labor, family farm, environmental, faith and social justice organizations” that formed in 1991 to fight NAFTA. “We have seen ongoing TPP negotiations do none of these things. Fast track will only make it worse.”

Wise said that is because “unelected ambassadors are able to completely ignore any congressional objective.”

Ignoring congressional objectives will kill any trade deal, countered Emmer, who replaced Tea Party favorite Michele Bachmann, a vocal opponent of trade promotion authority.

“I knew all along how important trade was to Minnesota, but all I ever heard was ‘fast track,’ ” Emmer said. “When you hear ‘fast track,’ you think someone is trying to pull a fast one.”

Emmer studied the issue and decided that was not the case. Trade promotion, he now tells anyone who will listen, is the best way for Congress to have a say in opening markets to sell American goods and create U.S. jobs.