JOHN YANG: We turn our focus back to Capitol Hill.

Earlier this evening, I sat down with Republican Senator Ben Sasse of Nebraska. We spoke before the Justice Department announced it was appointing Robert Mueller as a special counsel in this investigation of the ties between Russian and the Trump campaign.

We looked at how the Republican Party’s leadership is handling the fallout, and the senator’s new book, “The Vanishing American Adult.”

Senator Sasse is a Republican who has been vocal for some time about his opposition to Mr. Trump.

I began by asking for his response to the recent events.

SEN. BEN SASSE, R-Neb.: Well, there’s just a lot we don’t know, so let’s first be humble about how little we know.

But it’s very important that we, those of us who are called to be public servants for a time, are constantly thinking about, what can we do to rebuild, not further erode public trust?

We have the institutions of our democratic republic that have 9 percent, and 12 percent, and 15 percent approval rating, and that’s not sustainable.

The Federal Bureau of Investigation is a really important institution, and we need to all want to shepherd it. We want it to be protected from political influence. We want it to not be a place that the American people think of as a partisan agency that they should doubt.

And so, very critical, when you have three branches of government, the executive branch is where you are going to have to put your investigative arm, the FBI, and your prosecutorial decision-making, the Department of Justice. But the American people need to have confidence that it’s insulated from political and partisan decision-making.

JOHN YANG: You have questioned — even in the campaign, you said you trusted neither candidate. You didn’t trust Mr. Trump. You didn’t trust Secretary Clinton.

As your colleagues have learned more, and as we have all learned more about President Trump, have you been satisfied with the way your colleagues, and especially the leadership, have reacted?

SEN. BEN SASSE: Well, I think both of these political parties are living on borrowed capital. And they’re exhausted. There aren’t clear visions that either party has right now.

I want to be clear, I’m the third or fourth most conservative guy in the Senate by voting record, but I’m not particularly partisan. We should be having a conversation between the two political parties, where they’re each trying to outdo each other in terms of having better ideas to persuade the American people about what a vision for 10 and 15 years and 20 years into the future should be for policy-making.

Instead, we constantly have a lesser of two evils conversation. And right now, both political parties tend to act like their main job is to explain yet why the other side is worse. That’s not good enough.

JOHN YANG: But is the discussion, the constant discussion of trying to explain or defend the president, is that getting in the way of not only the Republican agenda, but also this greater discussion that you talk about?

SEN. BEN SASSE: Yes.

I mean, we have a continuum that should be Republican vs. Democrat or conservative vs. progressive continuum about what policy-making the federal government should do. But most of our policy-making discussions are…