The House of Representatives opened historic impeachment hearings on Wednesday, with William B. Taylor Jr. and George P. Kent, senior career civil servants, caught in the crossfire. Democrats underscored the constitutional import of the proceedings, while Republicans branded the whole investigation into President Trump’s dealings with Ukraine a sham. Mr. Taylor and Mr. Kent — carefully, if cinematically — detailed the emergence of a shadow foreign policy, one which had the capacity to determine the fate of an ally in the face of Russian aggression.  We discuss what this phase of the impeachment inquiry could mean for the president — and for the 2020 election. Guest: Michael S. Schmidt, who covers national security and federal investigations for The New York Times. For more information on today’s episode, visit nytimes.com/thedaily.  Background reading: Mr. Taylor said that, in a call with Gordon D. Sondland, the American ambassador to the European Union, President Trump had made clear he cared “more about the investigations of Biden” than Ukraine’s security.Here are key moments from the first public impeachment hearing.