Pelosi launches impeachment inquiry into Trump

House Speaker Nancy Pelosi (D-CA) announces the House of Representatives will launch a formal inquiry into the impeachment of U.S. President Donald Trump following a closed House Democratic caucus meeting at the U.S. Capitol in Washington, U.S., September 24, 2019. Photo credit: Kevin Lamarque/Reuters

For months, House Speaker Nancy Pelosi resisted the mounting calls from her caucus to start impeachment proceedings. But she said her tipping point was the recent revelation that President Trump pressured the Ukranian president to investigate Joe Biden and his son.