In October 2019, a whistleblower anonymously complained that U.S. President Donald Trump, his lawyer Rudy Giuliani, and other high-ranking Trump administration members had made phone calls with Ukrainian presidentVolodymyr Zelensky, asking him to have the Ukrainian government investigate Joe Biden, who was a candidate in the 2020 Democratic primaries at the time; as well as his son Hunter Biden in exchange for keeping U.S. military aid to Ukraine going.[2] The complaint raised concerns that Trump was asking for other countries to interfere in the 2020 presidential election.[3]