House Speaker Nancy Pelosi formally announced an impeachment inquiry against President Trump over a possible quid pro quo and abuse of power in foreign relations with Ukraine.

Under our Constitution, impeachment is a formal accusation made by the House of Representatives. Any such accusation, once made by a majority of the House, goes to the Senate. That body then conducts a trial of these charges, voting on whether to convict the president of them. If two-thirds or more vote to convict, the president is removed from office.