In the Declaration of Independence, American revolutionaries listed their grievances against the British king. Among his offenses, they said, was “cutting off our Trade with all parts of the world.”

What a shame that a few members of Congress now think that another of our founding documents stands in the way of modern trade policy. In a letter last month, they actually claimed to believe that Trade Promotion Authority (TPA) violates the Constitution.

This is absurd—and for our export-fueled economy to meet even modest goals in global commerce, we can’t let this bizarre interpretation of the Constitution cut off our trade in the 21st century.

The letter, organized by Rep. Walter Jones of North Carolina and signed by 23 members of Congress, begins plainly enough: “We are strong supporters of American trade expansion. We are also strong supporters of the U.S. Constitution.”

So far, so good.

But then the letter veers in a strange direction. It complains that TPA denies Congress the ability to oversee U.S. trade policy.

Nothing could be further from the truth.

Our Constitution, Article I:  Section 8 says that Congress will “regulate Commerce with foreign Nations.” And that’s why TPA guarantees that Congress approve any trade treaty before it becomes the law of the land. Under TPA, only trade deals that receive explicit approval from Congress go into effect.

This is not theory, but actual practice. TPA—sometimes going by its earlier name of “Fast Track”—has allowed Congress to vote on all of America’s trade deals, from big ones, such as the North American Free Trade Agreement, to modest ones, such as the accords with Panama and Singapore. None has gone forward without a clear endorsement from Congress.

Taken together, these agreements have strengthened the U.S. economy, creating export opportunities for American farmers and manufacturers and lowering prices for consumers.

They’re also a bipartisan success story, enabling lawmakers to reach across party lines. To expand trade opportunities, President Reagan collaborated with a Democratic majority in Congress and President Clinton worked with a Republican majority in Congress.

TPA is necessary for a simple reason: Our trading partners need to know that when they sit down at the bargaining table with the United States, they’re dealing with a single representative—and not 535 individual members of Congress, many of them embodying narrow interests and promoting separate agendas.

So traditionally the White House works with leaders in Congress to establish the goals of a trade deal. Then our trade diplomats negotiate with representatives from other countries. If they can reach terms that promise to improve our economy, they strike a tentative agreement, which the president submits to Congress for final consideration, in an up-or-down vote.

It’s an excellent system that has worked well for a long time, keeping true to the Constitution and also promoting our economy in a variety of partisan environments.

Congress of course must remain vigilant, always ready to reject a trade deal that doesn’t make sense. This includes agreements that cede too much authority to international organizations. Although every negotiation involves give and take, we must never become party to a pact that surrenders our sovereignty.

International trade is one of the keys to U.S. success—it’s a small bright spot in an otherwise sluggish economy. That’s why our lawmakers must strive to improve the ability of Americans to buy and sell goods and services with people in other countries. Two current negotiations hold great promise: the Trans-Pacific Partnership (TPP) with a group of nations around the Pacific Rim, and the Transatlantic Trade and Investment Partnership (TTIP), which would improve our ties with the EU.

We should hope that both of these talks succeed—but without TPA, neither will move beyond the most initial stages of conversation.

All members of Congress should not hesitate to support TPA, confident that it will boost the economy and fulfill the constitutional imperatives to promote the general welfare and secure the blessings of liberty.

Tim Burrack raises corn, soybeans and pork on a NE Iowa family farm.  He serves as Vice Chairman and volunteers as a Board Member of Truth About Trade and Technology ( Follow us: @TruthAboutTrade on Twitter | Truth About Trade & Technology on Facebook.