Senate Minority Leader Chuck Schumer vowed to fight President Donald Trump’s Supreme Court nominee after the President lashed out at the federal judge who blocked his executive order suspending the country’s refugee program and temporarily barring visitors from seven predominantly Muslim countries.

“The President’s attack on Judge James Robart, a Bush appointee who passed with 99 votes, shows a disdain for an independent judiciary that doesn’t always bend to his wishes and a continued lack of respect for the Constitution, making it more important that the Supreme Court serve as an independent check on the administration,” Schumer said in a Saturday statement.

“With each action testing the Constitution, and each personal attack on a judge, President Trump raises the bar even higher for Judge Gorsuch’s nomination to serve on the Supreme Court. His ability to be an independent check will be front and center throughout the confirmation process,” the minority leader added.

Trump published a tweet on Saturday morning criticizing the order and calling U.S. District Judge James Robart a “so-called” judge.

Robart issued an order Friday night blocking Trump’s order nationwide. The order prompted the State Department to begin reinstating visas it had revoked and the Department of Homeland Security to end efforts to enforce the executive order.