Impeachment -- the 'I' word -- and how it works

The past week has seen extraordinary political turmoil in Washington, as President Donald Trump faces grave accusations that he has obstructed justice.With the White House running damage control, and critics smelling blood, some Democrats have mentioned the "I" word -- impeachment -- as a possibility for the 45th president, although initiating the procedure remains a hypothetical.The Republican leader faces allegations he asked his FBI director James Comey to halt a probe of a senior former advi