While Senator Marco Rubio (R-FL) ditched his planned speaking appearance at the Conservative Review Convention in South Carolina on Thursday, Senator Ted Cruz (R-TX) reportedly lit up the packed hall.

Rubio’s team claims a scheduling conflict prevented his appearance, but many observers believe Rubio skipped the event out of concern that the crowd and major participants favored Cruz; Conservative Review’s major invitees, like Mark Levin, Michelle Malkin, and David Limbaugh, are significantly more sympathetic to Cruz than to Rubio, particularly on issues of immigration.

Cruz, meanwhile, appeared to a massive ovation before 5,000 South Carolinians. Cruz opened by stating that he tried to think about what Levin would tell him: “Ted, keep it short: defend the Constitution, repeal Obamacare, and kill the terrorists. And I’ve gotta say, that pretty much sums it up.”

Cruz then moved to his key message: the urgency of filling the void left on the Supreme Court by Justice Antonin Scalia’s death.

Cruz said, “Justice Scalia was an American hero. Justice Scalia was a lion of the law, he loved the Constitution, he loved freedom. I had the blessing of knowing Justice Scalia for 20 years…Justice Scalia, in three decades on the court, changed the arc of American legal history, singlehandedly shifted the Constitution and the interpretation of it back to the original understand, back to the text and words adopted by the framers. As Ronald Reagan was to the presidency, so too Justice Scalia was to the US Supreme Court. And his passing leaves an enormous void on the Court…Our very Bill of Rights hangs in the balance. We have right now an activist, out of control Supreme Court. But we are one justice away from a five-justice radical left-wing majority the likes of which this country has never seen.”

Cruz asked the crowd to ask themselves: “Who can I trust?”

Cruz talked about his legal background as Solicitor General for Texas, about organizing resistance to partial-birth abortion on the federal level. He said, “We are one liberal justice away from the Supreme Court striking down every meaningful restriction put on abortion over the last 40 years….You know, the most significant decision, majority opinion of Justice Scalia’s tenure was the case of Heller vs. District of Columbia.”

Cruz mentioned that he represented gun owners before the Supreme Court. “And we won,” Cruz concluded, “5-4. Five to four. We’re one justice away…the dissenters didn’t say that some gun control laws are occasionally permissible. Instead, what the dissenters said was that the Second Amendment does not protect any individual right whatsoever. They said it was merely a ‘collective right of the militia,’ which is essentially fancy lawyer talk for a nonexistent right. One more liberal justice and the Supreme Court will effectively write the Second Amendment out of the Constitution.”

Cruz then moved on to religious liberty. He mentioned defending the 10 Commandment monuments on state capitol grounds. Again, they won 5-4. “We are one liberal justice away from the court mandating that Ten Commandments monuments be torn down…all over this country,” Cruz stated.

Finally, Cruz mentioned Medellin vs. Texas, a case in which a gang murdered and assaulted little girls. One of the murderers was an illegal immigrant; the World Court issued an order to reopen the convictions of 51 murderers. Texas stood up and defeated the UN, Cruz said. Cruz said that he argued against the Bush Administration (he also swiped at Donald Trump by stating “unlike some people in this race, I don’t think he should have been impeached”). Cruz won the case, and the Court ruled that the UN had no authority over the US justice system, and no president has the constitutional authority to give away American sovereignty. Cruz added, “We are one liberal justice away from the Supreme Court handing over authority to the United Nations and the World Court and international law and undermining the sovereignty of we the people of the United States.”

Cruz summed up that Scalia’s passing had underscored the fact that “it is not one but two branches of government that hang in the balance.” Cruz pointed out that Democrats always get it right: their nominees are always consistent. “Republicans,” said Cruz, “bat less than .500.”

Why? Cruz said, “It’s not that Republicans secretly want to put Republicans on the Court. It’s that we’ve had too many Republican presidents who don’t value the Court, value the Constitution enough to spend the political capital to confirm a real conservative.” Cruz railed against “stealth candidates…If you’ve lived fifty years of your life and you’ve never said or written or done anything to demonstrate you’re a conservative, you ain’t.”

That, too, was a nicely-disguised slap at Trump.

Cruz concluded: “Here are the stakes of this election. If, God forbid, we elect Hillary Clinton or Bernie Sanders or some other socialist, we will lose the Court for a generation. But if, God forbid, we elect some Republican who makes the same mistakes as the Republicans of the past…we will see our fundamental rights undermined for a generation. And I believe the question the men and women of South Carolina are asking, is ‘Who do I know, beyond a shadow of a doubt?’” Cruz then vowed to nominate only Constitutionalists who would protect the Bill of Rights. He said, “We can’t get burned again. We’ve been burned too many times.”

Cruz then moved on to why he was most qualified for commander-in-chief. He mentioned clarity of vision, strength of resolve, and temperament, among other characteristics. He talked about rebuilding the military at length, and ripped political correctness for destroying military policy.

But his real point was the first: Cruz’s pitch that he is the most knowledgeable and capable candidate when it comes to choosing the next Supreme Court justice. Cruz’s fluency on the subject is obvious, and his expertise and principle are unparalleled. Scalia’s death does indeed make clear that we cannot afford another leftist justice. And regardless of who wins the nomination, Cruz ought to be the man picking the next deciding vote on the Supreme Court.

Ben Shapiro is Senior Editor-At-Large of Breitbart News, Editor-in-Chief of DailyWire.com, and The New York Times bestselling author, most recently, of the book, The People vs. Barack Obama: The Criminal Case Against The Obama Administration (Threshold Editions, June 10, 2014). Follow Ben Shapiro on Twitter @benshapiro.