Republican presidential candidates faced off Saturday evening for the last time before next week's South Carolina primary.

CBS moderator John Dickerson began the broadcast with a moment of silence for Justice Antonin Scalia, the leading conservative on the Supreme Court whose death was announced hours before the debate Saturday. This show of respect for the deceased segued quickly into a discussion on who should fill his newly vacant seat on the high court.

Scalia's Replacement

Donald Trump was the first candidate to weigh in on the future of the Supreme Court, calling Justice Scalia's death a "tremendous blow to conservatism." He urged Senate Majority Leader Mitch McConnell to delay President Obama's likely appointment of a new justice.

Ohio Gov. John Kasich expressed his concern that an appointment by Obama would start another partisan fight in Washington, D.C. He said the president should not move forward and should let the voters chose the next president to appoint the new justice.

Marco Rubio praised Scalia for his interpretations of the Constitution.

"The Constitution is not a living and breathing document. It's to be interpreted as originally meant," the Florida senator said.

Jeb Bush said the next president needs to appoint someone who has a proven conservative record and is a "lover of liberty" like Justice Scalia.

Ben Carson and Texas Sen. Ted Cruz shared the sentiment that Obama would not be the right authority to chose the next Supreme Court justice.

National Security & Foreign Policy

When asked what three questions he would ask of national security advisors, Donald Trump said he would ask "what we want to do, when we want to do it, and how hard we want to hit." The real estate mogul said the U.S. needs to carefully assess its allies, citing the disgrace of the Iran deal and the possibilities of working with Russia to fight ISIS. He expressed his desire to "attack the oil and keep the oil" in efforts to take the wealth away from the Middle East.

Rubio spoke about the threats the U.S. faces in the Asia Pacific region (China and North Korea) and the Middle East (Syria's Assad and ISIS), as well as the threats to NATO in the Europe (by Russia). He said that he voted against Obama's plan to use force against Assad in the past because the attack would have made the situation worse and facilitated Assad staying in power.

Carson was questioned about his lack of experience in foreign policy. He said his decision making skills and willingness to try things that have never been done before would help him as commander in chief.

"Judgement is what is required," the retired neurosurgeon said.

Kasich said in order to ensure national security, the U.S. needs to arm Ukraine because "an attack on NATO is an attack on us."

"The world is desperate for our leadership…the world needs us," the Ohio governor said.

Bush said the U.S. needs to go after both ISIS and Assad. He criticized Trump for suggesting that Russia could be a partner in the Middle East.

Trump shot back insisting that the U.S. needs to eliminate ISIS before going after Assad.

Cruz said the greatest threat facing the U.S. is the threat of a nuclear Iran. He went after President Obama and Hillary Clinton's focus on "nation building." The Texas senator said the U.S. needs to focus on fighting ISIS with air power and should arm the Kurds to fight on the ground.

Dickerson questioned Cruz about how the Kurds could destroy ISIS on the ground as they are not good at fighting outside of their own territory. Cruz emphasized again that the U.S. should start with its strong airpower abilities.

Trump criticized the Iraq War and Jeb Bush's initial hesitancy to speak out for or against the actions of his brother's administration.

Bush said he was sick and tired of the attacks on his family.

"While Trump was building a reality TV show, my brother was building a security apparatus to keep us safe," Bush said.

Kasich cut into the fighting between Trump and Bush.

"This is crazy. This is just nuts," Kasich said about the bickering.

The Ohio governor said the U.S. made a mistake getting involved in a civil war in the Middle East and should only go to war when it's in the country's best interest.

Rubio expressed his gratitude to former President George W. Bush for keeping the country safe after the 9/11 attacks. Trump, though, repeatedly pointed to the attack on the World Trade Center as the antithesis to the argument that the elder Bush brother kept the country safe when he was in charge.

Trump and Rubio went back and forth arguing over whether President Bush or President Bill Clinton should be blamed for the instability in the Middle East.

Carson blamed the Obama administration for the destabilizing the region. He said a commander in chief needs to assess the consequences of his or her actions.

The Economy

Trump was asked if he could feasibly deliver on his economic promises. He responded saying he would save Social Security, bring jobs back, lower taxes and bring money back from offshore banks.

"We have to make our economy great again. This country is dying," Trump said.

When asked to be more specific about his plans to save Social Security, the real estate mogul said he would eliminate waste, fraud and abuse, citing "thousands" of 106-year-old recipients on the books.

Cruz spoke about lessening the burden on businesses and changing the tax code by creating a flat 10 percent income tax and a business flat tax.

Rubio said he would create an additional child tax credit so parents could keep more of their money.

"The family is the most important institution in society. You can't have a strong country without strong families," Rubio said.

Kasich defended Medicaid, saying it can be used to treat the mentally ill and addicts so the country doesn't spend money taking care of them in prisons. He aligned himself with Reagan, stating that the former president also expanded Medicaid.

Bush emphasized his anti-Obamacare position and said the tax code needed simplified rates to shift power away from Washington and stimulate job growth.

Carson said in his tax policy, everyone will have to contribute and the corporate tax rate would be equalized with every other tax rate.

When asked if financial executives should be held responsible for the country's financial crisis, as Democratic candidate Bernie Sanders so often asserts, Carson said the U.S. needs to start trimming regulatory agencies.

Cruz said young people, Hispanics, African Americans, and single moms were hurt by the big government policies of the Obama administration. He cited the story of his Cuban immigrant father's rise to financial stability in his call to lift the burdens on small businesses. The Texas senator said he would get people off of welfare and back to work.

Trump said that the president's executive orders are a "disaster" and that the U.S. was being hurt by trade pacts. He explained that business needed to be brought back to America.

Immigration

Trump said the United States needs to take care of its own citizens. He once again advocated for a wall financed by Mexico along the southern U.S. border.

"If we don't have borders, if we don't have strength, we don't have a country," Trump said.

Rubio said he does not support amnesty and that the U.S. needs to strongly enforce the law before it does anything else regarding illegal immigration.

Rubio and Cruz then both insisted that the other was pro-amnesty and had changed his position on immigration.

Bush said the U.S. needs a leader to fix the problem of illegal immigration. He argued that coming to the country legally should be easier than coming illegally. The former Florida governor said that although he does not support illegal immigration, not all illegal immigrants have bad intentions so they should be treated with respect.

Kasich promised to have plan for addressing illegal immigration within the first 100 days of his presidency, including sealing the border and creating a guest worker program. He said that it was not a realistic goal to deport every illegal immigrant.

Flip-Flopping & In-Fighting

The focus then moved to Trump's criticism of Cruz's changes in opinion, while comparing his own altering views to the shift of former President Ronald Reagan.

Trump criticized Cruz for changing his opinion on immigration, but said that flexibility was necessary. He explained that he is a "common sense conservative," which causes him to adhere to what he believes are the best views given the circumstances. The real estate mogul stood by his use of eminent domain in his business practices.

Bush took this as an opportunity to speak out against Trump's (and his brother's) support for eminent domain, saying it shouldn't be used in the personal interests of businesses.

Cruz responded to Trump's attacks, stating that flexibility is a good thing, but you shouldn't be flexible on core principles. He called out Trump for not condemning federal tax payer support for Planned Parenthood.

Trump called Cruz a liar and a "nasty guy," to which Cruz shot back that when you criticize Trump's shifting views, he automatically calls you a liar.

Trump explained his stance on Planned Parenthood. He said he was anti-abortion, but supports the other services that the organization supplies for women's health.

Cruz warned the audience that if Trump were elected, he would appoint liberals.

Rubio then changed the topic to the issue of poverty. He said that anti-poverty programs have become a "way of life" for some people and expressed his desire to turn these programs over to the state governments.

Carson then got the chance to speak after trying to interject in the Trump-Cruz bickering. He said the Republican party cannot afford to lose this election and needs to stop tearing each other down. The famed neurosurgeon said that the country needs a president who will support the American dream and that "irresponsible, evil" government needs to be stopped.

Kasich was asked about his label of "Democrats' favorite Republican." The Ohio governor said he didn't mind the support, especially from the "blue-collar Democrats" who could find hope in his message.

Trump distanced himself from the established government officials on stage by explaining that politicians are "all talk and no action." He also had the chance to clear up his past uses of profanity, saying that it was used to highlight his points and that "not using profanity is very easy."

Bush said the country needed a uniter and someone with a "proven record who can forge consensus to solve problems."

Rubio was then asked what question he would ask of any former president. He called Obama the "worst president in 35 years" (since Jimmy Carter) and said he would ask Reagan how he inspired the American people to believe in the future.

Closing Statements

Kasich ended with the statement that "the spirit of America rests in all of us."

Carson emphasized the importance of "spiritual life, patriotism, and morality." He said that as president, he would be "accountable to everybody and beholden to no one."

Bush expressed the need to unite the people around a common purpose. He cited his accomplishments as governor and promised to focus on the American people instead of polls.

Rubio began his closing by explaining the challenges facing the U.S., stating that "America's reputation is in decline." He then, however, went on to say that 2016 could be a turning point for the country if the next president could "re-embrace free enterprise," stand up for conservative social values and build up the U.S. military.

Cruz explained that following Scalia's death, "two branches of government hang in the balance." He said as president, he would defend the Constitution and the Bill of Rights, and defeat enemies and keep the country's borders safe.

Trump was the last candidate to speak, once again saying that politicians are "all talk and no action." He emphasized his campaign slogan that he is "going to make our country great again" because the U.S. doesn't "win" anymore.

"I'm working for you. I'm not working for anybody else," the businessman said.

And with that, the GOP candidates concluded their last appeals to the voters of South Carolina before the state's Republican primary.

The primary is on February 20. Follow Annenberg Media for more coverage of the 2016 elections.

Reach Staff Reporter Alison Main here.