Opposition Democrats are moving ahead with their impeachment inquiry of President Donald Trump, even as the administration blocks key witnesses from testifying and has been slow to provide documents. Eventually, Democrats may vote to impeach Trump over his dealings with Ukraine in the House of Representatives where they have a majority. That would lead to an impeachment trial in the Senate where the president and his Republican supporters have a distinct advantage and as of now would likely vote to acquit him. VOA National correspondent Jim Malone has more on the president’s political firewall from Washington. VOA Khmer's Leakhena Sreng narrates.