Forget the art of the deal. Donald Trump has perfected the art of distraction.

His ability to continuously change the subject has kept Trump alive through bankruptcies, failed marriages, the collapse of his online university, numerous lawsuits and other calamities.

As President Trump, though, the ability to distract could prove deadly — especially if he and national security adviser John Bolton and Secretary of State Mike Pompeo persuade the public that the United States should go to war with Iran. The attacks last week on two oil tankers in the Gulf of Oman — attacks the U.S. is claiming were carried out by the Iranians — were just the latest indication that Washington wants a war. What better distraction going into a presidential year, after all?

That’s why legislation introduced in April by New Mexico Sen. Tom Udall must be heard and debated. Seldom has a piece of legislation been as timely as Udall’s bipartisan bill to prevent war with Iran, coming as it is during a time of escalating tensions with the Middle Eastern country.

Senators from both the Republican and Democratic parties must step up to take back for Congress the power to declare war. Presidents from both parties have usurped power handed to Congress in the U.S. Constitution and involved the United States in undeclared, never-ending wars. Udall’s legislation — the Prevention of Unconstitutional War with Iran Act — seeks to stop the U.S. from spending money that could lead to war with Iran. For those funds to be spent, Congress must approve. That’s the way it should be.

Udall’s bill underscores that Article 1, Section 8 of the Constitution of the United States grants to Congress the sole power to declare war, stating that any preemptive attack against Iran would be illegal under both the War Powers Act and the Constitution. That’s not to say, however, that the U.S. should not respond to an imminent military threat from Iran or defend U.S. citizens who are threatened with harm; the legislation also makes that clear.

This is commonsense policy, designed to rein in an unchecked executive and reminding all that only Congress has the constitutional power to go to war. Udall long has shown consistency over the years, voting against the Patriot Act in 2001 and against the Iraq War in 2002, while supporting authorization of military force against Iraq, a more limited option than a declaration of war. He continues to demand that a president must make the case for war to citizens and to Congress before the United States spends precious lives or treasure.

As Udall said in a statement about his legislation, “One of the most important lessons of Iraq is that all it takes for a tragic debacle of a war to start is inaction or silence from those who know better. That’s why we must act now to assert Congress’ authority, and block an unconstitutional war that lacks congressional authorization.”

Sen. Rand Paul, a Republican from Kentucky, has signed on as a co-sponsor, as have several Democratic presidential candidates, including Sens. Elizabeth Warren, Cory Booker, Kristin Gillibrand, Michael Bennet and independent Sen. Bernie Sanders. New Mexico Sen. Martin Heinrich also is a co-sponsor. Some 26 senators are supporting the legislation to date.

At a powerful speech last week at the Center for American Progress, Udall made the case for Congress taking back its war powers authority: “It’s frightening but true, we could be caught in a war based on a mistake or miscalculation, or a manufactured crisis reminiscent of the run-up to the war in Iraq. John Bolton’s commitment to regime change in Iran and the president’s Twitter-trigger finger are why Congress needs to step in and halt the march to war.”

He called for Congress to show “backbone” and take back its authority, despite the likelihood that Senate Majority Leader Mitch McConnell would prevent a vote on this legislation, as he does on so many bills. In that case, Udall said, the issue of war and Congress’ role in declaring it must become a major issue in the 2020 presidential election.

“We are a democracy, with checks and balances. It’s our duty to remain vigilant,” Udall said.

Tom Udall is leaving the Senate in 2020. In these last months, he is doing some of his most consequential work, reminding the country that Congress has a job it has evaded for too long. No more, the senator said: “Congress needs to step up and all of us need to stand up and show we don’t roll over for another endless war.”