Nothing as far as the government is concerned. It's up to the party to promote the v.p. nominee or find a new nominee. If the ballots are printed that's an issue governed by the laws of the individual states. If the states grant the power to the electoral college, then even if the guy AND the V.P. candidate were dead the E.C. would still get the votes and have the power to elect.
The 20th Amendment provides that if the President-elect dies before inauguration "the Vice President-elect shall become President". However, a President elect does not legally become such until the members of the Electoral College cast their votes in December, so if a "President-elect" died before that, his electors would have to vote for someone else (probably his Vice-Presidential running-mate) since votes for a dead man would not be counted. If it were the Vice-President elect who died, then if the Electors had not yet voted, his party could nominate another candidate. If however they had already voted for him, the President-elect would be sworn in without a Vice-President, and would then have to appoint one under the provisions of the 25th Amendment.
The Democratic Party's nominee for vice president in the 1864 presidential elections was George Pendelton. He was the running mate of the Party's presidential nominee George B. McClellan.
They are chosen by the same convention that nominates the president. Lately the presidential nominee has chosen his running mate. The usual strategy is to "balance the ticket" by picking someone who will run well in states that the presidential candidate is weak in, or to pick someone who can deliver the votes in a key state, such California or New York. If there is a divergent of views in the party, the vice president nominee may be chosen from the minority group in order to placate them and make them want to work harder for the ticket.
The nominee himself (herself) once sure of the party ticket. If after the party has chosen he/she will need party approval.
Joseph Biden , the incumbent is running for another term as VP.
Barack Obama's vice presidential running mate was Senator Joe Biden.
The VP candidate is chosen by a vote of the delegates after they choose the presidential candidates. In recent years the presidential nominee has told the convention whom he wants and the convention has acceded to his choice. However this was not always the case and may not be the case in future.
idiotsRufus King was the Federalist Party Vice Presidential Nominee in 1804 and 1808 and their Presidential Nominee in 1816. He lost all three elections.Martin Van Buren was the Democratic Party Vice Presidential Nominee in 1832 and their Presidential Nominee in 1836 and 1840. He won the first two elections and lost the third.John C. Breckinridge was the Democratic Party Vice Presidential Nominee in 1856 and their southern Presidential Nominee in 1860. He won in 1856 and lost in 1860.Franklin D. Roosevelt was the Democratic Party Vice Presidential Nominee in 1920 and their Presidential Nominee in 1932, 1936, 1940 and 1944. He won every time except 1920.Richard M. Nixon was the Republican Party Vice Presidential Nominee in 1952 and 1956 and their Presidential Nominee in 1960, 1968 and 1972. He won every time except 1960.Hubert H. Humphrey was the Democratic Party Vice Presidential Nominee in 1964 and their Presidential Nominee in 1968. He won in 1964 and lost in 1968.Walter Mondale was the Democratic Party Vice Presidential Nominee in 1976 and 1980 and their Presidential Nominee in 1984. He won the first election and lost the next two.George H. W. Bush was the Republican Party Vice Presidential Nominee in 1980 and 1984 and their Presidential Nominee in 1988 and 1992. He won every time except 1992.Bob Dole was the Republican Party Vice Presidential Nominee in 1976 and their Presidential Nominee in 1996. He lost both elections.Al Gore was the Democratic Party Vice Presidential Nominee in 1992 and 1996 and their Presidential Nominee in 2000. He won the first two elections and lost the third.(I did not include John Adams in this list because although he was understood to be a vice presidential candidate in 1788 and 1792, as were several who ran before 1804, officially there were no vice presidential elections before 1804; they were all officially presidential candidates. For those keeping score, Mr. Adams won the Vice Presidency in 1789 and 1792, won the Presidency in 1796, and lost in 1800. Also, although Thomas Jefferson was Vice President when he was elected President in 1800, it was never his intention to run for Vice President. However, he won the Vice Presidency in 1796 because he received more votes for President than John Adams' running mate, Thomas Pinckney.)
Mitt Romney was a former governor and businessman and is now running against Barack Obama in the Presidential Election as the Republican nominee.
The Democratic Party's nominee for the U.S. Presidential Election of 1988 was Michael Dukakis, and his running mate was Geraldine Ferraro. The Democrats' nominee in 2000 was Vice President Al Gore, and his running mate was Joe Lieberman.
The two men who ran for Vice President were Joseph Biden (Democrat) and Paul Ryan (Republican). Since President Obama won re-election in 2012, and Joe Biden was his running-mate, Mr. Biden won a second term as Vice President.
Jimmy Carter ran against Gerald Ford in 1976 for president, with Carter winning the presidency.
Vice presidents are usually elected jointly as a running mate to the president. The electoral college elects the President and the President chooses the Vice President. a Presidential candidate selects "their" own V.P, but is nominated and elected by party convention