2019 Trump–Ukraine scandal

The 2019 Trump–Ukraine political scandal arose primarily from the discovery of U.S. president Donald Trump's attempts to coerce Ukraine into investigating his political rival Joe Biden and thus potentially damage Biden's campaign for the 2020 Democratic Party presidential nomination. Trump enlisted surrogates in and outside his administration, including personal lawyer Rudy Giuliani and Attorney General William Barr, to pressure Ukraine and other governments to cooperate in supporting and legitimizing the Biden–Ukraine conspiracy theory and other conspiracy theories concerning U.S. politics.

Source: Wikipedia — 2019 Trump–Ukraine scandal (CC BY-SA 4.0)