House Democrats plan to sue the Trump administration over the president’s attempts to reauthorize funds for a southern border wall, House Speaker Nancy Pelosi announced on Thursday.

In February, President Donald Trump declared a national emergency in an effort to obtain roughly $8 billion in funding for the border wall, a last-ditch effort he made after Congress declined to fulfill an earlier spending request. House Democrats haven’t filed their suit yet, but they intend to take to the courts and argue that this move was unconstitutional, Pelosi said.

Trump has, after all, ignored the will of Congress — the body that’s authorized to approve federal spending by the Constitution — not once, but twice. After Congress rejected Trump’s initial demands for border wall money, it also passed a resolution aimed at blocking his national emergency — a clear sign that the majority of the body disagreed with his efforts. (Trump issued the first veto of his term to reject that resolution.)

“The President’s action clearly violates the Appropriations Clause by stealing from appropriated funds, an action that was not authorized by constitutional or statutory authority,” Pelosi said in a statement on Thursday. “Congress, as Article I — the first branch, co-equal to the other branches — must reassert its exclusive responsibilities reserved by the text of the Constitution and protect our system of checks and balances.”

One of the key questions House Democrats will face with this lawsuit is whether they have the legal standing to sue in the first place. Plaintiffs must prove that there is harm being caused in order to secure standing.

Interestingly enough, House Republicans may have actually set a precedent that could make Democrats’ case for standing more viable.

House Republicans established a precedent for suing the White House over appropriations

House Democrats plan to sue the White House on the grounds that it is effectively bypassing Congress’s constitutional power of the purse, the same logic Republicans used in a 2014 lawsuit against the Obama administration.

At the time, Republicans argued that officials had attempted to use federal funds that had not been approved by Congress to pay insurers under the Affordable Care Act. In that case, a federal judge ruled that Republicans had the grounds to sue the White House because its efforts infringed on Congress’s authority over appropriations. Because Trump is now trying to reauthorize funds that were originally appropriated for other purposes, legal experts say Democrats can, once again, use this same argument and emphasize that he’s circumventing Congress by doing so.

House Democrats could also contest the status of the national emergency by arguing that it’s not actually an emergency at all, though experts have said that the law has typically granted the president wide latitude to determine what an emergency is.

Whichever arguments they ultimately use, House Democrats are far from alone in making them. The American Civil Liberties Union and 20 states are also suing the president over the use of the national emergency to obtain funding for the border wall.