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Robert Mueller defended his team of prosecutors and his hiring practices after Republican Rep. Kelly Armstrong claimed they had conflicts of interests.

During his remarks, Armstrong began naming members of Mueller's team and their alleged biases and ties to Hillary Clinton.

Mueller interrupted Armstrong and asked if he could address his hiring practices.

"We strove to hire those individuals that could do the job. I've been in this business for almost 25 years, and in those 25 years, I have not had occasion once to ask somebody about their political affiliation. It is not done. What I care about is the capability of the individual to do the job and do the job quickly and seriously and with integrity," Mueller said.

Armstrong argued back, saying, "It's simply not enough you vouch for your team."

"But that's what I'm saying, Mr. Mueller. This isn't just about you being able to vouch for your team. This is about knowing the day you accepted this role, you had to be aware no matter what this report concluded half of the country was going to be skeptical of your team's findings," he said.

It was Mueller's first response to a narrative that President Trump has pushed — that the special counsel’s office was comprised of “angry Democrats.”

CNN has reported that some of the members of Mueller’s team made donations to Democrats. Andrew Weissman, a senior member of the team, also attended Hillary Clinton’s election night party in 2016 and lavished praise on former deputy attorney general Sally Yates, an Obama appointee, in an email after she Trump and did not enforce his travel ban executive order in early 2017.

Mueller said Weissmann played “some role” in the hiring of special counsel team members, but “not a major role.” Mueller said he did not know remember when he found out that Weissmann had attended the Clinton party and said he would not talk about the Yates email.

Earlier in the hearing, Mueller offered support for Weissmann. “He is one of the more talented attorneys that we have on board. Over a period of time he has run a number of units” at the Justice Department," Mueller said.

CNN's David Shortell contributed to this post.