The Trump administration’s campaign to dismantle the Education Department drew a pair of court challenges on Monday, as opponents called the plan an attempt to evade congressional authority.
The first lawsuit was filed in federal court in Massachusetts by the American Federation of Teachers, a teachers union; the American Association of University Professors; and two public school districts in Massachusetts. Within hours the N.A.A.C.P., the National Education Association union and other critics had brought a case of their own in federal court in Maryland.
The challenges came four days after President Trump signed an executive order that directed the education secretary, Linda McMahon, to “take all necessary steps to facilitate the closure of the department.”
The day after the order, Mr. Trump announced that the Small Business Administration would assume control of the government’s $1.6 trillion student loan portfolio, and that the Health and Human Services Department would oversee nutrition programs and special education services.
The Education Department, created in 1979, cannot be closed without Congress’s consent. The Massachusetts lawsuit argues that the Trump administration’s moves since it came to power in January, including an effort to roughly halve the department’s work force, “will interfere with the department’s ability to carry out its statutorily required functions.”
Ilana Krepchin, chairwoman of the Somerville, Mass., school committee, which is a plaintiff in the Massachusetts case, said that the Education Department was a “cornerstone of equitable public education.”
“Dismantling it would cause real harm — not only to our students and schools, but to communities across the country,” Ms. Krepchin said.
Madi Biedermann, a spokeswoman for the Education Department, said that all federally mandated programs would remain in the agency and that the administration had promised to work with Congress in order to close the department.
“Instead of focusing on the facts and offering helpful solutions to improve student outcomes, the union is once again misleading the American public to keep their stranglehold on the American education bureaucracy,” Ms. Biedermann said, referring to the American Federation of Teachers.
Top Republicans on Capitol Hill — including Senator Bill Cassidy of Louisiana, chairman of the Senate Committee on Health, Education, Labor and Pensions — have pledged to support the president’s push, which has been embraced by some right-leaning groups.
But rank-and-file lawmakers are expected to face significant pressure, both for and against the plan, before any vote is held.
Charles L. Welch, the president of the American Association of State Colleges and Universities, said last week that he was “dismayed” by Mr. Trump’s order and urged lawmakers to, in effect, defy the White House and help preserve the department.
The Education Department has limited power over what is taught in American classrooms. Its principal jobs are to distribute money to schools, enforce civil rights laws and run the federal student aid program for college students. It has historically played a large role in data collection and education research funding.
It is not clear when any legislation to close or rebuild the department might come to a vote.
In the Maryland case, the N.A.A.C.P. and the N.E.A., the nation’s largest teachers’ union, were among the plaintiffs who argued that the administration’s tactics over the last two months amounted to “a de facto dismantling of the department by executive fiat.”
“Donald Trump’s own secretary of education has acknowledged they can’t legally shut down the Department of Education without Congress,” said Aaron Ament, president of the National Student Legal Defense Network, which is helping represent the National Education Association in the case.
“Yet that is, for all intents and purposes, exactly what they are doing,” he added. “It’s a brazen violation of the law that will upend the lives of countless students and families.”
Derrick Johnson, president and chief executive of the N.A.A.C.P., accused Mr. Trump of doing far more than trying to shrink or shutter an agency.
“Education is power,” Mr. Johnson said. Referring to Mr. Trump, he added, “He is deliberately destroying the pathway many Americans have to a better life.”
The N.A.A.C.P. and the other challengers in Maryland asked a federal judge to prohibit the Education Department and Ms. McMahon “from continuing their dismantling of the department and implementing the March 20 executive order.”
In a separate, privacy-focused case also in Maryland, a federal judge ruled on Monday that the Education Department could not supply sensitive data to the Department of Government Efficiency, which is led by Elon Musk.