President Trump’s insulting and immature treatment of neighboring Canada and its elected leader, combined with his unhinged ranting about trade deficits, intensifies the need for Congress to reassert its constitutional authority to regulate commerce with other nations.

Unfortunately, that seems highly unlikely. In control of Congress, the Republican Party, which once had as among its central tenets supporting free trade, is now the party of Trump, willing to live with his vision of protecting favored industries with tariffs and forcing markets to bend to his will rather than that of competition.

The result of this is likely to be higher consumer prices and a reduced ability of the United States to use its innovation to compete globally.

Arriving late and leaving early, President Trump attended the G-7 meeting in Quebec this weekend with the leaders of the nation’s strongest democratic-led democracies — Germany, Britain, France, Japan, Canada and Italy.

There Trump encountered unified resistance from these allies to his notions that the United States is being treated terribly by its friends when it comes to trade and his increasing use of tariffs that bring with them the risk of a trade war that could drag down their collective economies.

And what exactly is Trump’s beef? What is so dire that it is worth weakening critical alliances and the world economic system? According to the U.S. Department of Commerce's export.gov site, the European Union imposes an average tariff of 3 percent on U.S. goods.

Canada does have a ridiculously high tariff on dairy products, but overall the two countries have been strong and open trading partners.

Adding to the tension was Trump’s suggestion that Russia should rejoin the group to again make it the G-8. This suggestion ignores the fact that Russia is in no way any longer a functioning democracy and it overlooks Russia’s seizing of Ukraine’s Crimean territory. On Monday, however, the administration announced new sanctions targeting Russia. Strategic consistency is not a strong point for the Trump White House.

The G-7 leaders seemed ready to put a good face on things with a communique intended to endorse both Trump’s demands for fairness, without diving into his version of what that constitutes, while reaffirming the alliance’s long-held support for free trade.

“We acknowledge that free, fair and mutually beneficial trade and investment, while creating reciprocal benefits, are key engines for growth and job creation,” it safely stated.

But when, after Trump’s departure, the host for the summit, Prime Minister Justin Trudeau, dared to make some comments for his domestic audience, Trump went ballistic. He withdrew his support for the statement and personally attacked the Canadian leader.

Trudeau told his fellow citizens that he let the U.S. president know that “Canadians did not take it lightly that the United States has moved forward with significant tariffs on our steel and aluminum industry.” If the situation does not change, said Trudeau, his nation would impose retaliatory tariffs. No surprise there.

Trudeau also made the valid point that Trump’s “national security” explanation for the tariffs and protection of the U.S. steel industry “is kind of insulting” to Canadians, because it suggests in a time of crisis they would not support their U.S. neighbor and longtime ally with steel supplies.

Most presidents would let it go. Some might offer a counter argument. Trump tossed insults, calling Trudeau “very dishonest and weak.”

Peter Navarro, a trade adviser to the president, topped his boss with a more outrageous comment on “Fox News Sunday.”

"There's a special place in hell for any foreign leader that engages in bad faith diplomacy with President Donald J. Trump and then tries to stab him in the back on the way out the door," said Navarro.

This is insanity and it is why Congress needs to reclaim the asylum, at least that section that deals with how the nation controls trade with our allies.

The U.S. Constitution is clear on who should be regulating trade, and it’s not the president.

“The Congress shall have the power to regulate Commerce with Foreign Nations,” states Article I, Section 8.

But Congress, in a series of bills passed over more than a century, has surrendered its authority by giving presidents legal justifications to regulate trade without congressional action.

The Republican Congress needs to show some backbone, reassert its authority, and give our allies some indication of a return to normalcy.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.