Question: Which president appointed the justice who wrote for a unanimous court in Smiley v. Citibank?

Context paragraphs:
Smiley v. Citibank (South Dakota), N. A.: Smiley v. Citibank, (517 U.S. 735), is a 1996 U.S. Supreme Court decision upholding a regulation of the Comptroller of Currency which included credit card late fees and other penalties within the definition of interest and thus prevented individual states from limiting them when charged by nationally-chartered banks.  Justice Antonin Scalia wrote for a unanimous court that the regulation was reasonable enough under the Court's own "Chevron" standard for the justices to defer to the Comptroller.

Andranik Margaryan: Andranik Nahapeti Margaryan (Armenian: Անդրանիկ Նահապետի Մարգարյան , alternative spelling: Andranik Margarian) (12 June 1952 – 25 March 2007) served as the Prime Minister of Armenia from 12 May 2000, when the President appointed him, until his death on 25 March 2007.  He was a member of the Republican Party of Armenia.  He succeeded the Sargsyan brothers: Vazgen Sargsyan, who was murdered during the Armenian parliament shooting on 27 October 1999 and Aram Sargsyan, whom the President appointed a week later, but fired on 2 May 2000.

Wisconsin v. Illinois: Wisconsin v. Illinois, 278 U.S. 367 (1929) also referred to as the Chicago Sanitary District Case, is an opinion of the Supreme Court of the United States which held that the equitable power of the United States can be used to impose positive action on one state in a situation in which nonaction would result in damage to the interests of other states.  Pursuant to Article Three of the United States Constitution, the case was heard under the Supreme Court's original jurisdiction because it involved a controversy between two states, Illinois and Wisconsin.  Chief Justice William Howard Taft wrote the opinion for a unanimous Court.

Antonin Scalia: Antonin Gregory Scalia ( ; March 11, 1936 – February 13, 2016) was an Associate Justice of the Supreme Court of the United States from 1986 until his death in 2016.  Appointed to the Court by President Ronald Reagan in 1986, Scalia was described as the intellectual anchor for the originalist and textualist position in the Court's conservative wing.

Zedner v. United States: Zedner v. United States, 547 U.S. 489 (2006) , was a United States Supreme Court case involving the right to a speedy trial.  Justice Samuel Alito, writing for a unanimous Court, ruled that a defendant cannot prospectively waive the protections of the Speedy Trial Act.  Justice Antonin Scalia filed a partial concurrence, objecting to Alito's use of legislative history.

Oliver Wendell Holmes Jr.: Oliver Wendell Holmes Jr. ( ; March 8, 1841 – March 6, 1935) was an American jurist who served as an Associate Justice of the Supreme Court of the United States from 1902 to 1932, and as Acting Chief Justice of the United States from January–February 1930.  Noted for his long service, his concise and pithy opinions and his deference to the decisions of elected legislatures, he is one of the most widely cited United States Supreme Court justices in history, particularly for his "clear and present danger" opinion for a unanimous Court in the 1919 case of "Schenck v. United States", and is one of the most influential American common law judges, honored during his lifetime in Great Britain as well as the United States.  Holmes retired from the Court at the age of 90 years, making him the oldest Justice in the Supreme Court's history.  He also served as an Associate Justice and as Chief Justice on the Massachusetts Supreme Judicial Court, and was Weld Professor of Law at the Harvard Law School, of which he was an alumnus.

Whorton v. Bockting: Whorton v. Bockting, 549 U.S. 406 (2007) , was a United States Supreme Court case about the application of the Confrontation Clause and whether "Crawford v. Washington" (2006) applied retroactively.  Justice Samuel Alito, writing for a unanimous Court, ruled that "Crawford" did not apply retroactively.

Owasso Independent School District v. Falvo: Owasso Independent School District v. Falvo, 534 U.S. 426 (2002) , was a case in which the United States Supreme Court held in favor of the school district that students scoring each other's tests and calling out the grades do not violate the Family Educational Rights and Privacy Act of 1974 (FERPA).  Justice Kennedy wrote the opinion for the unanimous court.  Justice Scalia wrote a concurring opinion in which he agreed with the ruling, but took issue with parts of Kennedy's opinion.

R (Canada) v Adams: Justice Sopinka wrote for a unanimous court in this appeal from the Alberta Court of Queen's Bench on a case in which a Criminal Code section 486 publication ban was overturned by the trial judge, Justice Feehan, after he had found the primary witnesses for both sides of a sexual assault trial to be unreliable.

Bronston v. United States: Bronston v. United States, 409 U.S. 352 (1973), is a seminal United States Supreme Court decision strictly construing the federal perjury statute.  Chief Justice Warren Burger wrote for a unanimous Court that responses to questions made under oath that relayed truthful information in and of themselves but were intended to mislead or evade the examiner could not be prosecuted.  Instead, the criminal-justice system had to rely on more carefully worded follow-up questions.

Supporting paragraphs: Smiley v. Citibank (South Dakota), N. A. Antonin Scalia
Answer: Ronald Reagan