(Reuters) - U.S. congressional Democrats are pursuing a fast-moving impeachment inquiry against President Donald Trump, focused on whether he abused his power by pressuring Ukraine to launch an investigation against a key political rival.
Democrats allege Trump temporarily withheld $391 million in U.S. military assistance to Ukraine as a way to pressure the country into investigating former Vice President Joe Biden -- a possible 2020 election challenger. A senior White House official has said the aid was linked instead to a request that Ukraine look into a debunked conspiracy theory about foreign interference in the 2016 U.S. presidential election, involving a Democratic Party computer server.