A group of 21 Democratic attorneys general are suing the Trump administration to block the dismantling of the Department of Education, alleging the firing of 50% of its employees "incapacitates" the Department's ability to compete its legally required functions.

The lawsuit, filed in Massachusetts federal court, asks a judge to immediately pause the Trump administration's mass firings and declare the dismantling of the Department of Education unlawful.

"This massive reduction in force is equivalent to incapacitating key, statutorily mandated functions of the Department, causing immense damage to Plaintiff States and their educational systems," the lawsuit said. "Far from being just a 'first step,' the layoffs are an effective dismantling of the Department."

The attorneys general allege that the 20 states and District of Columbia who brought the case would suffer irreparable harm from the dismantling of the department, arguing the federal government is "deeply intertwined" with their education systems through funding for low-income children, support for students with disabilities, federal student aid, and laws that prevent discrimination in education.

According to the lawsuit, the reduction in force would prevent the department from completing its legally mandated functions, and that neither Trump nor Education Secretary Linda McMahon have the authority to break down a department created by Congress.

-ABC News' Laura Romero, Aaron Katersky and Peter Charalambous

The White House on Thursday pulled President Donald Trump's nomination of Dr. David Weldon to lead the Centers for Disease Control and Prevention, multiple sources told ABC News.

The move came moments before Weldon was set to testify before the Senate HELP Committee. The hearing was canceled.

David Weldon, a former Republican congressman tapped to lead the Centers for Disease Control and Prevention, will face questions from lawmakers at his confirmation hearing at 10 a.m. ET before the Senate Health, Education, Labor and Pensions Committee.

Weldon, if confirmed, will work closely with Health Secretary Robert F. Kennedy Jr. Like Kennedy, Weldon has a history of questioning vaccine safety.

A focus of Thursday's hearing is likely to be the rising number of measles cases across the U.S.

President Donald Trump is scheduled Thursday to welcome NATO Secretary General Mark Rutte to the White House.

The pair are expected to hold an Oval Office meeting, after which they'll have a working lunch.

The meeting comes amid heightened international discussions about European and U.S. defense spending. The president and his allies have often criticized the military alliance, saying that the United States pays more than its fair share.

NATO members agreed in 2006 to commit to defense spending equal to at least 2% of their GDP. Twenty-three of the 32 members hit that target in 2024, according to the Atlantic Council.

Rutte, who took over leadership of the military alliance in October 2024, spoke with Trump in late February, with the pair then agreeing "on the importance of Europe and Canada significantly increasing defense spending and defense industrial capacity," according to a readout from Rutte's office.

Questions about defense spending have since then been ricocheting throughout Europe, in part because the Trump administration has questioned whether it should continue funding Ukraine's fight against Russia's invading army.

European leaders last week held an emergency summit in Brussels, Belgium, to discuss both the bloc's defense spending and security guarantees for Ukraine.

-ABC News' Hannah Demissie and Kevin Shalvey