Trump was impeached by House last month on charges that he abused his power like no other president, jeopardizing Ukraine and U.S.-Ukraine relations. Democrats say Trump asked the vulnerable ally to investigate Joe Biden and debunked theories of 2016 election interference, temporarily halting American security aid to the country as it battled Russia at its border. The second article of impeachment says Trump then obstructed the House probe in a way that threatened the nation’s three-branch system of checks and balances.