If Joe Biden were to win the 2020 presidential election with Barack Obama as his running mate and subsequently pass away, it is unclear if Obama would become the president. The Constitution of the United States grants the Vice President the authority to assume the presidency in the event of the president's death, resignation, or removal from office. However, if a new Vice President has not been confirmed by the Senate, the Speaker of the House of Representatives would assume the presidency. Therefore, if Joe Biden were to pass away and Barack Obama had not yet been confirmed as the Vice President, the Speaker of the House would become the President of the United States.