In a Washington paralyzed by partisan division, there is apparently one area of bipartisan agreement: Congress should ignore its constitutional mandate to vote on war with the Islamic State, a conflict that President Obama admits will take years.

The president says he’d “welcome” congressional support but doesn’t need it. Democratic leaders Rep. Nancy Pelosi (Calif.) and Sen. Harry Reid (Nev.) agree. Republican House Speaker John Boehner (Ohio) argues Congress should postpone any debate until next year. He allows it might be in the “nation’s interest” for members of Congress to weigh in, but it certainly isn’t an imperative. The leaders of Congress treat their own body as vestigial, offering little beyond symbolic gesture on the vital question of war and peace.

This bipartisan consensus about expanding the executive’s war-making powers directly contradicts the Constitution of the United States. The Founders gave Congress, not the president, the power to declare war. Their purpose was clear. War was the instrument by which kings and dictators consolidated power and impoverished nations. They feared that the executive by its nature was more given to war. James Wilson, a delegate to the Constitutional Convention, summarized the consensus: Giving the power to Congress “will not hurry us into war; it is calculated to guard against it. It will not be in the power of a single man, or a single body of men, to involve us in such distress.”

The Founders assumed that the Republic would generally be at peace. Except to repel imminent attack, any decision to go to war would be made by the legislature, after extended debate. The legislature would debate before the war started, before casualties were taken, before patriotic fevers spiked.

In an important speech to the National Defense University last year, President Obama noted that “we must define the nature and scope of this struggle, or else it will define us, mindful of James Madison’s warning that ‘No nation could preserve its freedom in the midst of continual warfare.’ ” He pledged to engage Congress in efforts to “refine, and ultimately repeal” the post-9/11 Authorization to Use Military Force (AUMF), and promised not to sign laws to “expand this mandate further.”

That promise apparently is, in Richard Nixon’s memorable phrase, “inoperable,” as the president now invokes the same AUMF as his authority for war on the Islamic State.

The Founders would not have been shocked at the executive seeking to claim the war power, but they would be astounded at Congress voluntarily giving it up.

Legislators don’t want to vote on authorizing the war for the same reason it is imperative that they do so: They would be accountable for the decision they make.

When President George W. Bush geared up to launch the war on Iraq, politicians with national ambitions lined up in support, many deeming it necessary for their political viability. But that catastrophic choice came back to haunt them, as exemplified by Hillary Clinton, who paid dearly for her vote in the 2008 Democratic primaries.

Voting on the war on the Islamic State is unpalatable. A majority of Americans, spooked by the beheadings and the lurid exaggeration of the threat posed by the Islamic State, now support the bombing. But most oppose putting U.S. forces on the ground, and few have any stomach for the long, violent, indeterminate struggle that an attack on the Islamic State is likely to be. Legislators know that the shock of the beheadings is but temporary. Continued American bombings will inevitably increase commitment, upheaval and costs, which will soon turn Americans sour on the new war. A peace movement has already started to stir and will grow as the price rises. Some legislators — mostly Democrats — have already begun to voice skepticism.

Politicians who vote to support what is certain to be a long, and likely losing, conflict will be at risk. But politicians who fail to vote for the war will be attacked as undermining forces already engaged in the battle. No wonder leaders of both parties agreed to punt on the vote until after the election, and likely until the next Congress. It is far safer to be an armchair general than to have your vote on the record for a war that turns bad.

This is a sorry dereliction of duty. This is not a partisan or a procedural matter. This is, as the president has said, about what kind of a country we are. “The choice we make about war,” he told us, “can impact – in sometimes unintended ways – the openness and freedom on which our way of life depends.”

As the “indispensable nation,” an America committed to police the world will be enmeshed in unending conflicts. This president, accused by Republicans bizarrely of isolationism, is now waging wars in Afghanistan, Iraq and Syria, intervened to overthrow a government in Libya, and is dropping bombs from drones in eight countries. The wars of today will surely generate tomorrow’s enemies.

The Founders envisioned Congress, comprised of legislators in close touch with the people in their states and districts, as a check on this imperial temptation for the executive. The only way that can happen is for Congress to exercise its power to declare war — or decide against it. And for voters to hold their legislators accountable for the choice they make.

The president had it right in his speech a year ago: “This war, like all wars, must end. That’s what history advises. That’s what our democracy demands.” Will Congress stand with the Republic or will its members simply duck and run for cover?

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