Democrats have launched yet another probe into the Trump administration. This time they are looking into the recent firings at the Department of Homeland Security.

According to The Hill:

Three top House Democrats on Thursday launched an investigation into what they described as “unprecedented firings” at the Department of Homeland Security.

House chairmen Elijah Cummings (D-Md.), Jerrold Nadler (D-N.Y.) and Bennie Thompson (D-Miss.) wrote a letter to Acting Homeland Security Secretary Kevin McAleenan demanding communications related to the departure or potential departure of former Homeland Security Secretary Kirstjen Nielsen, former Secret Service Director Randolph Alles and other officials.

“We are deeply concerned that the firing and forced resignation of these officials puts the security of the American people at risk,” the lawmakers wrote.  “We are also concerned that the President may have removed DHS officials because they refused his demands to violate federal immigration law and judicial orders.”

“Moreover, we are concerned by reports that, even as he has removed the Department’s leadership, the President has sought to empower a White House aide, Stephen Miller, to ‘be in charge of handling all immigration and border affairs,’” the Democrats wrote.

The announcement of the probe comes on the heels of the White House’s refusal to let Stephen Miller testify before Congress.