Trump Impeachment: Vice President Mike Pence Aide Testifies In Inquiry

National security aide to Vice President Mike Pence arrived in Congress on Thursday to testify in the impeachment inquiry against President Donald Trump. Jennifer Williams listened to Trump's controversial July 25 phone call with Ukraine leader Volodymyr Zelensky, and could either support or dampen allegations that Trump abused his powers by pressuring Zelensky to investigate Trump's possible 2020 election rival. Democrats allege that Trump held up $391 million in military aid for Ukraine to force Zelensky to find dirt on Democrat Joe Biden, and also to find evidence supporting a widely discredited theory that Ukraine helped Democrats in the 2016 election.

Earlier, Donald Trump Jr, son of the US President, published on Wednesday the name of the alleged anonymous whistleblower whose complaint fired the impeachment inquiry against his father, breaking strict conventions for protecting officials who reveal wrongdoing in government. Amid calls by the president himself to expose the whistleblower, Donald Trump Jr. tweeted the name of a CIA analyst which has circulated online for weeks, and linked to a Breitbart news article implying the person was pro-Democrat and anti-Trump.

Democrats have accused Trump of abuse of power and illegally leveraging US military aid for political favors from a foreign country-- a quid pro quo that Trump denies.

Republicans painted the whistleblower, who had worked on the White House national security council earlier this year, as a Democratic Party supporter who lacked direct knowledge of the July 25 call.

But the call record and subsequent testimony to the impeachment inquiry by officials support the allegations that Trump withheld aid to pressure Zelensky to dig up dirt on Biden and the Democrats.

In testimony released Tuesday, close Trump ally Gordon Sondland, the US ambassador to the European Union, admitted he had told a senior Ukraine official that the aid would not be released until Zelensky fulfilled Trump's demands.