Exclusive-As US navigates summer of strikes, Biden's top labor adviser exits, source says FILE PHOTO: U.S. President Biden hails U.S. railway labor agreement following talks in WashingtonBy Nandita Bose(Reuters) -President Joe Biden's top labor adviser, Celeste Drake, has stepped down, according to a source with direct knowledge of the matter, as the administration attempts to maintain labor peace and avoid threatened strikes during an election year. At the White House, Drake advised Biden and his team on labor negotiations that had a direct impact on the country's supply chain and the economy, current and former White House officials said. The White House did not comment on Drake's potential successor. Another key Biden labor adviser, Erika Dinkel-Smith, was recently promoted to the position of senior labor adviser within the White House's Office of Political Strategy, the source added. She took over the position from Biden's former top labor adviser Seth Harris.