On December 18, 2019, Donald Trump became the third president in US history to be impeached by the House of Representatives. He was later acquitted by the Senate. Earlier that summer, Trump held a phone call with President Volodymyr Zelensky of Ukraine. An unknown whistleblower raised concerns about the call, claiming that Trump had improperly pressured Zelensky to get involved in US politics. Over the following months a dramatic impeachment inquiry...