Democrats ask whether Trump abused his office

After an explosive statement by a CIA whistleblower, US legislators are examining evidence that Donald Trump used his presidency to pursue a personal vendetta, writes Brad Heath

US president Donald Trump pressed his Ukrainian counterpart to investigate a political foe. Now, a central question for Democratic legislators moving with remarkable speed to impeach him is the extent to which Trump entangled both his office and the machinery of the US government to spark investigations that would benefit him personally.