Sunday on ABC’s  “This Week,” while discussing the replacement for Supreme Court Justice Antonin Scalia, Republican presidential candidate Sen. Ted Cruz (R-TX) said of his opponent Donald Trump that the time for the circus and reality show was over when it come to choosing a commander-in-chief that will uphold the Constitution.

Partial transcript as follows:

CRUZ: But Justice Scalia’s passing also has a profound impact on this primary. It underscores the stakes for the people of South Carolina. They’re looking at the individuals on that stage. They’re asking, who can I trust? Who do I know will defend the Constitution and will defend the Bill of Rights? Because the pattern we’ve seen, George — and you’re a veteran of these battles for many years. Democrats understand the stakes and they fight tooth and nail for left-wing judicial activists. Far too many Republicans don’t care about the court, don’t invest political capital in it. And it’s why so many Republican nominees have turned out to be disasters. And let me say something…

STEPHANOPOULOS: One of them that…

CRUZ: — in particular to the veterans of the state of South Carolina. To the veterans in South Carolina, your Second Amendment rights are hanging in the balance. Justice Scalia, one of his biggest opinions was the “Heller” decision. It was 5-4, upholding the individual right to keep and bear arms. If an additional liberal justice goes to the court, we’re one justice away from the Second Amendment being written out. And if Donald Trump becomes president, the Second Amendment will be written out of the Constitution because it is abundantly clear that Donald Trump is not a conservative. He will not invest the capital to confirm a conservative. And so the result would be the same —

(CROSSTALK)

STEPHANOPOULOS: He says he will.

CRUZ: — whether it’s Hillary, Bernie or Donald Trump. The Second Amendment will go away.

STEPHANOPOULOS: He says you’re wrong. He says he will and he says your judgment should be questioned because you supported John Roberts.

CRUZ: Listen, number one, I did not appoint John Roberts. George W. Bush did. Now once the president made the appointment, I supported that nomination. That was a mistake. But I would have — I would have appointed Mike Luttig, my former boss, Scalia’s very first law clerk. And more broadly, you’ve got to look at Donald Trump’s history. This is a man who, for four decades, has supported liberal Democrats. Donald Trump supported Jimmy Carter over Ronald Reagan. Donald Trump gave money to Chuck Schumer, to Harry Reid, to Hillary Clinton. Donald Trump supported John Kerry over George W. Bush. Now, let me tell you, George, anyone that writes checks to Chuck Schumer and Harry Reid and Jimmy Carter and Hillary Clinton does not care about conservative justices on the court. Donald Trump himself — you know, the one person he has suggested that would make a good justice is his sister, who is a court of appeals judge appointed by Bill Clinton. She is a hardcore pro- abortion liberal judge. And he said she would make a terrific justice. So the people of —

STEPHANOPOULOS: He has also said —

(CROSSTALK)

CRUZ: — South Carolina need to know —

STEPHANOPOULOS: — conflict of interest there —

CRUZ: — if you — if you vote —

STEPHANOPOULOS: — and he would not appoint her.

CRUZ: — it — but it gives you an example of the type of people he would be looking to, the type of people he would be looking to. Donald Trump is not a conservative. For his entire life, he has been, self-described, very, very pro-choice. He supported partial birth abortion. You know, yesterday, he defended Planned Parenthood and federal taxpayer funding for Planned Parenthood on the debate stage. George, have you ever seen a Republican on a Republican debate stage defending taking federal taxpayer money and giving it to Planned Parenthood? He said he thinks they do terrific things.

STEPHANOPOULOS: It certainly has —

CRUZ: I don’t think Planned Parenthood does terrific things. And I don’t think the conservatives of South Carolina do, either.

STEPHANOPOULOS: It certainly has been a long time. I have — I have never seen you unload on Donald Trump like you just have in the last couple of minutes.Is that because you’re concerned that, if he wins South Carolina, he can’t be stopped?

CRUZ: What I’m concerned about, George, is our country is in balance. I’ve devoted my entire life to fighting to defend the Constitution and the Bill of Rights. The Heller decision, I represented 31 states in Heller defending the Second Amendment. We won that case. You know, we’ve talked about abortion restrictions. I represented a coalition of states defending the federal ban on partial birth abortion. We won that case 5-4. I don’t want to see our liberties taken away. You know, my daughters, Caroline and Catherine, are 7 and 5. I don’t want to have to look at my daughters and say the freedoms that America has had for two centuries, you don’t get because we didn’t step up and pull it back. And Justice Scalia’s passing, I think, really changes the entire contours of this race. The time for the circus and the reality show is over. This is a serious choice and we are talking about losing our basic liberty if we get this wrong. And it’s way I have so much faith in the people of South Carolina that they value liberty, they value the Constitution. And I’ll tell you one final point, which is we’re also choosing a commander-in-chief. This is a dangerous world and it doesn’t make any sense to appoint someone — to elect someone as commander in chief who doesn’t understand the nature of our enemy. You know, last night, Donald Trump defended his calling for George W. Bush to be impeached. That is not consistent with the Constitution and it — and those are the views of the fever swamps of the Left. That’s where Donald comes from is the fever —

STEPHANOPOULOS: That is —

CRUZ: — swamps of the Left. He’s supporting John Kerry and saying let’s impeach George W. Bush. That is not a commander-in-chief fit to keep this country safe.

Follow Pam Key on Twitter @pamkeyNEN