The groups said the freeze violates Congress’ wishes and is endangering lives in developing countries.
The cuts would slice $4 billion from the budgets of universities and research organizations.
Judge Angel Kelley issued a restraining order.
The move by 22 state attorneys general comes after the National Institutes of Health announced on Friday that it would slash billions in university funding.
The Trump political appointees are leading the agency’s “collaboration” with Elon Musk’s team.
It’s the latest lawsuit pushing back on the Trump administration’s shakeup of the federal government.
The Louisiana Republican said he hoped Robert F. Kennedy Jr. would be “a partner” in promoting good health.
As a doctor, Cassidy is troubled by RFK Jr. As a politician, he has reason to support him anyway.
His statement comes as signs increasingly point to the Trump administration folding the development aid agency into the State Department.
Kennedy’s approval by the committee is far from certain.