President Donald Trump’s executive order challenging birthright citizenship will face its first legal test in a Seattle courtroom Thursday.

A federal judge will hear a request made by four Democratic-led states to issue a temporary restraining order against the executive order signed by Trump that purports to limit birthright citizenship to people who have at least one parent who is a United States citizen or permanent resident.

Trump’s executive order reinterpreting the 14th Amendment’s guarantee of birthright citizenship — long promised by Trump on the campaign trail — is expected to spark a lengthy legal challenge that could define the president’s sweeping immigration agenda.

Democratic attorneys general from 22 states and two cities have sued Trump over the executive order, and the president faces at least five separate lawsuits over the policy.

In addition to the hearing in Seattle, a federal judge in Maryland is holding a hearing by telephone on Thursday in a challenge brought by two nonprofit groups and five pregnant undocumented women.

U.S. District Judge John Coughenour — who was nominated to the bench by President Ronald Reagan in 1981 — scheduled Thursday’s in-person hearing in the case brought by the attorneys general of Arizona, Oregon, Washington and Illinois. In a federal complaint filed on Tuesday, the four attorneys general argued that Trump’s policy would unlawfully strip at least 150,000 newborn children each year of citizenship entitled to them by federal law and the 14th Amendment.

“The Plaintiff States will also suffer irreparable harm because thousands of children will be born within their borders but denied full participation and opportunity in American society,” the lawsuit says. “Absent a temporary restraining order, children born in the Plaintiff States will soon be rendered undocumented, subject to removal or detention, and many stateless.”

The lawsuit argues that enforcement of Trump’s executive order would cause irreparable harm to the children born from undocumented parents by preventing them from enjoying their right to “full participation and opportunity in American society.”

“They will lose their right to vote, serve on juries, and run for certain offices,” the complaint says. “And they will be placed into lifelong positions of instability and insecurity as part of a new underclass in the United States.”

Lawyers for the Department of Justice, now under new leadership, opposed the request for a temporary restraining order in a court filing Wednesday.

Taking effect next month, Trump’s executive order seeks to reinterpret the 14th Amendment’s guarantee of birthright citizenship by arguing a child born in the United States to an undocumented mother cannot receive citizenship unless his or her father is a citizen or green card holder.

While most countries confer a child’s citizenship based on their parents, the United States and more than two dozen countries, including Canada and Mexico, follow the principle of jus soli or “right of the soil.”

Following the Civil War, the United States codified jus soli through the passage of the 14th Amendment, repudiating the Supreme Court’s finding in Dred Scott v. Sanford that African Americans were ineligible for citizenship.

“President Trump and the federal government now seek to impose a modern version of Dred Scott. But nothing in the Constitution grants the President, federal agencies, or anyone else authority to impose conditions on the grant of citizenship to individuals born in the United States,” the states’ lawsuit argued.

The Supreme Court further enshrined birthright citizenship in 1898 when it found that the San Francisco-born son of Chinese immigrants was an American citizen despite the Chinese Exclusion Act restricting immigration from China and prohibiting Chinese Americans from becoming naturalized citizens.

By seeking to end birthright citizenship, Trump’s executive order centers on the same phrase within the 14th Amendment — “subject to the jurisdiction thereof” — that the Supreme Court considered in 1898. Trump’s executive order argues that text of the 14th Amendment excludes children born of parents who are not “subject to the jurisdiction” of the United States, such as people who are unlawfully in the U.S.

While legal scholars have expressed skepticism about the legality of Trump’s executive order, the lawsuit could set the stage for a lengthy legal battle that ends up before the Supreme Court.