Deputy Attorney General Rod Rosenstein appeared before Congress today to defend the impartiality of special prosecutor Robert Mueller and his investigation into the Trump campaign's ties with Russia.

"If there were good cause, I would act. If there were no good cause, I would not," Rosenstein said and added that he did not see any good cause to fire Mueller at this time.

Homeland security expert and Zemcar CEO Juliette Kayyem said Rosenstein's defense sends a message to the White House not to interfere with Mueller's investigation.

"I would say the deputy attorney general has missed no opportunity to make it clear to the Trump White House, which is probably listening along, that he has high confidence in Robert Mueller and his team," Kayyem said.

Rosenstein's defense comes at a time when some Republicans have accused Mueller and his investigation of bias. The accusations center around recently released text messages between two F.B.I employees that were critical of Trump. Mueller removed one of the employees, F.B.I. agent Peter Strzok, from the Russia investigation this summer.

Kayyem believes that Rosenstein's testimony was a rebuff to those accusations.

"I think Rod [Rosenstein], the deputy attorney general, used this opportunity to say, 'Whatever's going on politically, you're going to have to go through me,'" Kayyem said.

"He is basically setting up a Saturday Night Massacre-type scenario for the White House," she continued.

The Saturday Night Massacre refers to President Richard Nixon's firing of Watergate special prosecutor Archibald Cox, which prompted the resignation of Attorney General Elliot Richardson and Deputy Attorney General William Ruckelshaus. 

Click the audio player above to hear more from Juliette Kayyem.