Question: What is the name of this American politician and member of the Democratic Party who serves as the senior United States Senator from Maryland, born in October 1943, and who noted that there is an international campaign to reopen the Halki Seminary?

Context paragraphs:
Sherrod Brown: Sherrod Campbell Brown (born November 9, 1952) is an American politician and author who is the senior United States Senator from Ohio, in office since January 3, 2007.  Brown is a member of the Democratic Party.  Before his election to the Senate, he was a member of the United States House of Representatives, representing Ohio's 13th congressional district from 1993 to 2007.  He previously served as the Ohio Secretary of State (1983–1991) and as a member of the Ohio House of Representatives (1974–1982).

John Thune: John Randolph Thune (born January 7, 1961) is an American politician and senior United States Senator from South Dakota, a member of the Republican Party.  He previously served as a United States Representative for South Dakota 's at-large congressional  .  He became South Dakota's senior senator with the retirement of Tim Johnson in 2015.  He is South Dakota's senior senator, having served as the GOP's Chief Deputy Whip in 2006, chairman of the Republican Policy Committee in June 2009, and Republican Conference Chairman in 2011, the third-ranking position in the Senate.  He has worked in politics and civic organizations since completing his MBA graduate degree.  He is also the current dean of South Dakota's congressional delegation.

Bill Nelson: Clarence William Nelson II (born September 29, 1942) is an American politician and a member of the Democratic Party who serves as the senior United States Senator from Florida, in office since 2001.  Nelson began his career in the Florida House of Representatives, where he served from 1972 to 1978.  He then served in the United States House of Representatives from 1979 to 1991.  In January 1986, Nelson became the first sitting member of the United States House of Representatives to fly in space.  He flew as a Payload Specialist on the Space Shuttle "Columbia".

Dick Durbin: Richard Joseph Durbin (born November 21, 1944) is an American politician who is the senior United States Senator from Illinois, in office since 1997.  He has been the Assistant Democratic Leader (whip), the second highest position in the Democratic Party leadership in the Senate, since 2005, serving as Minority Whip from 2005 to 2007, Majority Whip from 2007 to 2015, and Minority Whip again since 2015.

Chuck Schumer: Charles Ellis Schumer ( ; born November 23, 1950) is an American politician, the senior United States senator from New York and a member of the Democratic Party.  First elected in 1998, he defeated three-term Republican incumbent Al D'Amato 55% to 44%.  Schumer was re-elected in 2004 with 71% of the vote, in 2010 with 66% of the vote, and in 2016 with 70% of the vote.

Halki seminary: The Halki seminary, formally the Theological School of Halki (Greek: Θεολογική Σχολή Χάλκης and Turkish: "Ortodoks Ruhban Okulu" ), was founded on 1 October 1844 on the island of Halki (Turkish: Heybeliada), the second-largest of the Princes' Islands in the Sea of Marmara.  It was the main school of theology of the Eastern Orthodox Church's Ecumenical Patriarchate of Constantinople until the Turkish parliament enacted a law banning private higher education institutions in 1971.  The theological school is located at the top of the island's Hill of Hope, on the site of the Byzantine-era Monastery of the Holy Trinity.  The premises of the school continue to be maintained by the monastery and are used to host conferences.  It is possible to visit the island where it is located via boat in approximately one hour from the shore of Istanbul.  As of January 2011, an international campaign to reopen this theological school is entering its 40th year as noted by American Senator Ben Cardin of Maryland in the United States Congress during the 2nd Session of Proceedings and Debates of the 111th Congress.

Ben Cardin: Benjamin Louis Cardin (born October 5, 1943) is an American politician and member of the Democratic Party who serves as the senior United States Senator from Maryland, in office since 2007.  Before his election to the Senate, Cardin was previously a member of the United States House of Representatives, representing  's 3 congressional district (1987–2007).  He also served in the Maryland House of Delegates (1967–87), serving as Speaker (1979–87).  He was the youngest Speaker in Maryland history.  In half a century as an elected official, he has never lost an election.

Mark Warner: Mark Robert Warner (born December 15, 1954) is an American businessman, politician, and the senior United States Senator from Virginia and a former governor.  He is a member of the Democratic Party and now serves as the vice chair of both the Senate Democratic Caucus and the Senate Intelligence Committee.

Patrick Leahy: Patrick Joseph Leahy (born March 31, 1940) is an American politician and the senior United States Senator from Vermont, since 1975.  A member of the Democratic Party, Leahy served as the President pro tempore of the United States Senate from December 17, 2012, to January 6, 2015.  As President pro tempore, he was third in the presidential line of succession.  He is the most senior senator and took office at 34 years old, younger than any other current senator.  Leahy received the title of President pro tempore emeritus upon the commencement of the 114th Congress.  He is the last remaining member of the Senate to have served prior to the 1976 election of President Jimmy Carter.

Claire McCaskill: Claire Conner McCaskill ( ; born July 24, 1953) is an American politician and member of the Democratic Party who serves as the senior United States Senator from Missouri.  She is the first female U.S. Senator elected in Missouri in her own right.

Supporting paragraphs: Halki seminary Ben Cardin
Answer: Ben Cardin