Bolton summoned; 1st big vote set on impeachment probe

FILE - In this July 31, 2019 file photo, National security adviser John Bolton speaks to media at the White House in Washington. (AP Photo/Carolyn Kaster)

President Donald Trump walks out of the North Portico of the White House in Washington, Monday, Oct. 28, 2019, to travel to Andrews Air Force Base, Md., and then on to Chicago. (AP Photo/Andrew Harnik)

WASHINGTON — House investigators are asking former national security adviser John Bolton to testify in their impeachment inquiry, deepening their reach into the White House as the probe accelerates toward a potential vote to remove the president.