In explosive testimony, the top U.S. diplomat in Ukraine, William Taylor, told congressional lawmakers Tuesday that the Trump administration held up $391 million in aid to Ukraine for the purpose of pushing Ukraine to incriminate Trump’s political rivals, particularly presidential candidate Joe Biden. In Taylor’s opening statement, which has been made public, he lays out his interactions with Gordon Sondland, the U.S. ambassador to the European Union and a wealthy Oregon hotel magnate who received the ambassadorship after donating $1 million to Trump’s inauguration. Taylor says Ambassador Sondland told him that “everything,” including security assistance, was dependent on Ukrainian President Volodymyr Zelensky announcing an investigation into Burisma, the gas company where Joe Biden’s son Hunter was a board member. Taylor said, “Ambassador Sondland told me that President Trump had told him that he wants President Zelensky to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 U.S. election.” Taylor’s testimony offers the most damning evidence so far in the ongoing impeachment inquiry.