1. Donald Trump was impeached on December 18, 2019 for abuse of power and obstruction of Congress, but was not formally convicted by the Republican-led senate;
2. The Impeachment was over the accusations that trump coerced the president of Ukraine to announce an investigation against Joe Biden, a possible political rival;
3. Mitt Romney was the only Republican to vote to convict trump on the charge of obstruction of congress;
4. An act which made Trump the third president ever to be impeached.
See also: Quid Pro Quo