Question: When did the Democratic senator in the United States vice-presidential debate of 1976 run for presidential election?

full_context: Document 1: Hubert Humphrey: Hubert Horatio Humphrey Jr. (May 27, 1911January 13, 1978) was an American politician who served as the 38th Vice President of the United States from 1965 to 1969. Humphrey twice served in the United States Senate, representing Minnesota from 1949 to 1964 and 1971 to 1978. He was the Democratic Party's nominee in the 1968 presidential election, losing to the Republican nominee Richard Nixon.
Document 2: Bob Dole: Robert Joseph Dole (born July 22, 1923) is an American lawyer and politician who represented Kansas in Congress from 1961 to 1996 and served as the Republican Leader of the United States Senate from 1985 until 1996. He was the Republican presidential nominee in the 1996 presidential election and the party's vice presidential nominee in the 1976 presidential election.
Document 3: United States Senate election in Kansas, 1992: The 1992 United States Senate election in Kansas took place on November 3, 1992. Incumbent Republican senator Bob Dole won re-election to a sixth term, defeating Democratic nominee Gloria O'Dell. Nearly two decades after his failed vice-presidential bid in 1976, this would be Dole's last election to the Senate. He would resign in 1996 while running for President of the United States. Dole also became the Republican Leader of the United States Senate seven years prior.
Document 4: Electoral history of Bob Dole: Electoral history of Bob Dole, United States Senator from Kansas (1969–1996), Senate Majority Leader (1985–1987, 1995–1996), Senate Minority Leader (1987–1995), 1976 Republican Party Vice Presidential nominee and 1996 Presidential nominee.
Document 5: United States vice-presidential debate, 1992: The 1992 vice-presidential debate was part of the 1992 presidential election. The participants were Democratic nominee, Bill Clinton's running mate, U.S. Senator Al Gore from Tennessee; Ross Perot's running mate, retired Vice Admiral James Stockdale; and Republican candidate, incumbent Vice President Dan Quayle. It was held on Tuesday, October 13, 1992.
Document 6: United States Senate election in Minnesota, 2002: The 2002 United States Senate election in Minnesota took place on November 5, 2002. Incumbent Democratic U.S. Senator Paul Wellstone was running for re-election to a third term, but died in a plane crash eleven days before the election. The Democratic-Farmer-Labor Party (DFL) chose former Vice President and 1984 Presidential candidate Walter Mondale to replace Wellstone on the ballot. Mondale lost to Republican Mayor of Saint Paul Norm Coleman. The day before the election, Independence Governor Jesse Ventura had appointed Dean Barkley (IP) to serve the rest of Wellstone's term. As of 2017, this is the last Senate election in Minnesota won by a Republican.
Document 7: 1976 Democratic National Convention: The 1976 Democratic National Convention met at Madison Square Garden in New York City, from July 12 to July 15, 1976. The assembled United States Democratic Party delegates at the convention nominated former Governor Jimmy Carter of Georgia for President and Senator Walter Mondale of Minnesota for Vice President. John Glenn and Barbara Jordan gave the keynote addresses. Jordan's keynote address made her the first African-American woman to deliver the keynote address at a Democratic National Convention. It was listed as #5 in American Rhetoric's Top 100 Speeches of the 20th Century (listed by rank). The convention was the first in New York City since the 103-ballot 1924 convention.
Document 8: Dan Quayle: James Danforth "Dan" Quayle (born February 4, 1947) is an American politician and lawyer who was the 44th Vice President of the United States from 1989 to 1993. He was also a U.S. Representative (1977–81) and U.S. Senator (1981–89) from the state of Indiana.
Document 9: United States Senate election in Montana, 1976: The 1976 United States Senate election in Montana took place on November 2, 1976. Rather than seek a fifth term, incumbent United States Senator Mike Mansfield, a Democrat, opted to retire, creating an open seat. United States Congressman John Melcher, who had represented Montana's 2nd congressional district from 1969 to 1977, won the Democratic nomination and defeated Stanley C. Burger, the Republican nominee, by a wide margin in the general election.
Document 10: Walter Mondale: Walter Frederick "Fritz" Mondale (born January 5, 1928) is an American politician, diplomat and lawyer who served as the 42nd Vice President of the United States from 1977 to 1981, and as a United States Senator from Minnesota (1964–76). He was the Democratic Party's presidential nominee in the United States presidential election of 1984, but lost to Ronald Reagan in a landslide. Reagan won 49 states while Mondale carried his home state of Minnesota and Washington, D.C.
Document 11: United States presidential election, 1996: The United States presidential election of 1996 was the 53rd quadrennial presidential election. It was held on Tuesday, November 5, 1996. The Democratic national ticket was led by incumbent President Bill Clinton, and his running mate, incumbent Vice President Al Gore. The Republican nominee for President was Bob Dole, the former Republican Leader of the United States Senate and long-time Senator from Kansas who was previously the vice-presidential running mate of President Gerald Ford in 1976, following Vice President Nelson Rockefeller's retirement from politics that year. Dole's running mate for Vice President was Jack Kemp, a former NFL football player and the Housing Secretary under George H. W. Bush. Businessman Ross Perot ran as candidate for the Reform Party with economist Pat Choate as his running mate; he received less media attention and was excluded from the presidential debates and, while still obtaining substantial results for a third-party candidate, by U.S. standards, did not renew his success of the 1992 election. Turnout was registered at 49.0%, the lowest for a presidential election since 1924.
Document 12: United States Senate election in Minnesota, 1984: The 1984 United States Senate election in Minnesota was held on November 6, 1984. Incumbent Republican U.S. Senator Rudy Boschwitz defeated Democratic challenger Joan Growe.
Document 13: Electoral history of George McGovern: George McGovern, a Democratic Party politician from South Dakota, was first elected to the United States House of Representatives to represent South Dakota's 1st congressional district in 1956. He was re-elected in 1958, before making an unsuccessful run for the United States Senate in 1960 against Republican incumbent Karl Earl Mundt. After serving in the John F. Kennedy administration as director of the Food for Peace program, McGovern ran again for the Senate and narrowly prevailed over appointed Senator Joseph H. Bottum. In 1968, McGovern unsuccessfully sought the Democratic Party's presidential nomination at the Democratic National Convention and was re-elected to the Senate over former Governor of South Dakota Archie M. Gubbrud. In 1972, McGovern was successful in his campaign for the Democratic presidential nomination, but lost the election in a landslide to incumbent President Richard Nixon. McGovern was re-elected to the Senate in 1974 over Vietnam War veteran Leo K. Thorsness, but lost re-election in 1980 to then-U.S. Representative James Abdnor. McGovern made a final unsuccessful run for president in United States presidential election, 1984.
Document 14: United States presidential election, 1976: The United States presidential election of 1976 was the 48th quadrennial presidential election, held on Tuesday, November 2, 1976. The winner was the Dark horse candidate Jimmy Carter, a former Governor from Georgia with his running mate, Walter Mondale, a U.S. Senator from Minnesota, the Democratic candidates, over the incumbent President Gerald Ford from Michigan and his running mate, Bob Dole, a U.S. Senator from Kansas, the Republican candidates.
Document 15: United States vice-presidential debate, 1976: This debate featured U.S. Senator Walter Mondale from Minnesota, the Democratic vice presidential nominee, and U.S. Senator Bob Dole from Kansas, the Republican vice presidential nominee.
ground_truth: 1984