Congressional Democrats want to limit President Donald Trump’s ability to take military action against Iran, and they’re planning to force a vote to get their point across.

In the coming weeks, both the House and the Senate will consider resolutions reiterating that Trump can’t use existing congressional military force authorizations to justify war against Tehran, and requiring him to curb any military action toward the country if Congress hasn’t specifically approved it.

Sponsored by Sens. Tim Kaine (D-VA) and Dick Durbin (D-IL) in the upper chamber and Rep. Elissa Slotkin (D-MI) in the House, these resolutions call on lawmakers to set up a check on the president’s ability to engage in further conflict with Iran. (Because lawmakers have said the two measures are similar to one another, we’ll be referring to them relatively interchangeably for simplicity’s sake.)

Democrats’ resolution marks their latest attempt to take a stand against both Trump’s recent use of an airstrike to kill Iranian Maj. Gen. Qassem Soleimani without congressional consultation, and the executive branch’s increasingly expansive interpretation of its war powers. Although the Constitution has established Congress as the body with the ability to declare war, the legislative branch has ceded more and more of its authority to the president over the years.

And while Congress hasn’t had the political will to actually hold new votes on America’s ongoing wars in Iraq and Afghanistan, Democrats and some Republicans have been increasingly eager to reassert themselves when it comes to military action elsewhere.

“I think it’s a pretty important statement from Congress about what the Constitution means,” Yale University law professor Oona Hathaway tells Vox about the resolution.

It is ultimately, however, just a message. Scheduling (or forcing) a vote on the resolution enables Democrats to make a point and put Republicans on the record, but this measure has little likelihood of being enacted. Not only is it expected to face Republican pushback, it would also be subject to Trump’s veto even if Congress winds up passing it.

And like other measures Democrats and bipartisan groups of lawmakers have tried passing in recent years, it’s not an airtight method for stopping all military action against Iran. Depending on differing legal interpretations on executive power, there are always exceptions, and it’s up to the administration to choose to respect it.

Democrats are using this resolution to make a point, though the president could potentially find a way around this measure, too

In a world where Democrats’ resolution passes Congress and is signed into law, it could tie Trump’s hands on Iran — as long the president didn’t find some way of working around it.

Kaine’s version, which he introduced last week, outlines a couple of different tenets: It requires the president to withdraw any additional armed forces from “hostilities” toward Iran 30 days after its passage by Congress and it emphasizes that lawmakers have not authorized military force against Iran.

Specifically, the resolution notes that the 2002 Authorization for Use of Military Force that was used to send troops to Iraq does not apply to any action the administration may be interested in taking in Iran. (That latter provision mirrors a similar bipartisan one that made it into the House’s annual defense spending bill last year, but the provision was removed in the final version negotiated with the Senate, much to the displeasure of progressives.)

Kaine’s measure also adds that the Trump administration itself has said that this authorization does not work, even though it’s been used quite broadly in the past to advance military efforts in Iraq and Syria.

The text of Slotkin’s resolution has not yet been released, though House Speaker Nancy Pelosi announced in a letter on Sunday that the House would vote on it this week.

The language in the two resolutions is set to closely resemble one another, and if Congress were to pass them it would establish a clear stance about how lawmakers on both sides of the aisle feel about the White House’s ability to unilaterally engage in armed conflict. “It’s a signal that Congress is willing to press for a renewed role in war powers,” says Hathaway.

There is an important caveat, however: Even if these resolutions become law, there’d be room for the president to maneuver around them, experts tell Vox.

“The Justice Department would probably take the position that the resolution infringed on the president’s constitutional authority, and so the president might very well ignore it,” the Brennan Center’s Liza Goitein says.

Ultimately, notes Brookings’s Scott Anderson, the interpretation of how constraining the resolution actually is is dependent on legal experts’ views about executive power and whether the president could justify the use of military force based on the authority granted by the Constitution.

“The truth is that the effect of a measure that imposes these restraints would be to shove the executive branch into uncharted legal territory,” Anderson says.

As Goitein explains, the DOJ via its Office of Legal Counsel “believes that the president has inherent authority under Article II of the Constitution to engage, without obtaining congressional authorization, in military actions that further important national interests and that fall short of total ‘war.’” Although there are past administrations that have said Congress could end these activities, Goitein argued that a Trump DOJ wasn’t likely to reach this conclusion.

Additionally, Hathaway notes that the Constitution offers an exception for the president to use military force without Congressional approval when the commander in chief is acting in response to a potential imminent attack. In an op-ed for the Atlantic, Hathaway argues that this may be why one of the White House’s main lines of defense has relied on the possibility of an imminent strike, which it has yet to provide evidence to back up:

Without any more solid legal authority to cite, the Trump administration seems to have turned to the claim that it was acting in self-defense. Though the administration has yet to provide any clear explanation for the legality of the strikes, it has offered various clues that the central justification is the president’s right to engage in self-defense on behalf of the United States. The Department of Defense issued a short statement suggesting that the attack was justified as an act of defense “aimed at deterring future Iranian attack plans.” Secretary of State Mike Pompeo later more forcefully claimed that the strike was aimed at disrupting an “imminent attack.” This claim—were it true—could solve the administration’s domestic and international legal problems at once. Both the U.S. Constitution and the UN charter include an exception for self-defense. Under Article II of the Constitution, the president may act to respond to imminent threats to the nation.

That said, if the president were to make a move in direct opposition of congressional majorities in both the House and the Senate, it would be a fairly stunning rebuke of the legislative branch, one that wouldn’t be expected to be taken lightly. A big question on both resolutions is how many Republicans end up voting alongside Democrats to support them.

These resolutions put pressure on Republicans

The prospects for the resolutions are uncertain at the moment. Given the Democratic majority in the House, it’s expected to pass there, while its chances are a bit slimmer in the Republican-controlled Senate. That said, because this is a war powers resolution, it is considered “privileged,” which means lawmakers will have to vote on it.

This dynamic suggests that all senators will have to go on the record about whether they support Trump continuing to increase military action in Iran, the likelihood of which has become a lot less theoretical since the last time they voted on this issue last summer. At that time, four Republican Senators — Rand Paul (R-KY), Mike Lee (R-UT), Susan Collins (R-ME), and Jerry Moran (R-KS) — broke with Trump to vote in favor of an amendment that would have cut off federal funding of military action against Iran that was taken without Congressional approval.

If Democrats were able to sway at least four Republicans to vote with them this time around, the resolution would be able to pass the upper chamber with a simple majority. Again, 51 senators is far from a veto-proof majority, but the vote would send a stinging signal to Trump and will force Republicans to show where they stand on further military engagement with Iran, a move that could see major pushback from the public and constituents in battleground states. According to a recent HuffPost/YouGov poll, 32 percent of independent voters disapprove of how Trump has handled foreign policy.

“If nothing else, if it doesn’t have the force of law to stop the president, it does provide an opportunity to have a bunch of Republicans forced to vote on the president’s decision and to rally political pressure against it,” Anderson told Vox.

Kaine has said as much himself, noting that this resolution is intended to prompt conversation about the role Congress plays when it comes to this type of intervention. “We owe it to our service members to have a debate and vote about whether or not it’s in our national interest to engage in another unnecessary war in the Middle East,” he said in a statement.

While its passage may be symbolic, the questions it raises are likely to endure far beyond these votes.