In a scathing speech on the Senate floor, the Arizona senator said the current political environment has caused elected officials like himself to remain silent when “we should speak, and silence can equal complicity.”

“I have children and grandchildren to answer to, and so, Mr. President, I will not be complicit,” Flake said on the Senate floor Tuesday. Flake said he would be better able to represent Arizona and serve his country and “conscience” by freeing himself from the “political considerations that consume far too much bandwidth and would cause me to compromise far too many principles.”

The move puts Republicans at risk of losing their 52-seat Senate majority in the midterm elections next year.

While Flake has said he agrees with some of Trump’s stances, the president has viewed the senator as an adversary.

Trump has publicly criticized Flake on Twitter multiple times. In August, for instance, Trump wrote “Great to see that Dr. Kelli Ward is running against Flake Jeff Flake, who is WEAK on borders, crime and a non-factor in Senate. He’s toxic!”

The reaction to Flake’s announcement has been widespread with both Democrats and Republicans weighing in.

.@JeffFlake is a good man who's in politics for all the right reasons. We need principled, decent public servants like Jeff more than ever.

— Mark Warner (@MarkWarner) October 24, 2017

.@JeffFlake is one of the finest human beings I've met in politics. He is moral, upright, strong & will be missed in the Senate.

— Chuck Schumer (@SenSchumer) October 24, 2017

“I have seen Jeff Flake stand up for what he believes in, knowing full well that there would be a political price to pay,” fellow Arizona Republican Sen. John McCain said Tuesday in an address to the Senate.

It’s been one of the great honors of my life to serve w/ @JeffFlake– a man of integrity, honor, decency & commitment to Arizona & the nation pic.twitter.com/DOHAoHx0d2

— John McCain (@SenJohnMcCain) October 24, 2017

Here are a few excerpts chosen by Fortune:

Flake’s opener

I rise to address a matter that has been very much on my mind at the moment when it seems that our democracy is more defined by our discord and dysfunction than our own values and principles.”

Let me begin by noting a somewhat obvious point that these offices that we hold are not ours to hold indefinitely. We are not here simply to mark time. Sustained incumbency is certainly not the point of seeking office. And there are times when we must risk our careers in favor of our principles.

Now is such a time.

Flake Says Enough

Mr. President, I rise today to say: Enough. We must dedicate ourselves to making sure that the anomalous never becomes normal.

With respect and humility, I must say that we have fooled ourselves for long enough that a pivot to governing is right around the corner, a return to civility and stability right behind it. We know better than that. By now, we all know better than that.

Flake Explains His Criticism

If I have been critical, it not because I relish criticizing the behavior of the president of the United States. If I have been critical, it is because I believe that it is my obligation to do so, as a matter of duty and conscience.

The notion that one should stay silent as the norms and values that keep America strong are undermined and as the alliances and agreements that ensure the stability of the entire world are routinely threatened by the level of thought that goes into 140 characters — the notion that one should say and do nothing in the face of such mercurial behavior is ahistoric and, I believe, profoundly misguided.

Flake On Truth

We were not made great as a country by indulging or even exalting our worst impulses, turning against ourselves, glorying in the things which divide us, and calling fake things true and true things fake. And we did not become the beacon of freedom in the darkest corners of the world by flouting our institutions and failing to understand just how hard-won and vulnerable they are.

His Closing Remarks