The New York Times reports:
Senate Republicans blocked a Democratic attempt on Tuesday to issue a subpoena summoning Mick Mulvaney, the acting White House chief of staff, to testify in President Trump’s impeachment trial. The 53-to-47 vote, which fell along party lines, was the latest effort by Democrats to force the inclusion of new evidence in the proceeding.
Mr. Mulvaney could still be summoned later under Republicans’ proposed rules, but only after opening arguments and a period in which senators can ask questions of the House managers and president’s lawyers is complete.
House Democrats subpoenaed Mr. Mulvaney in the fall during their inquiry, but he defied the order. Any similar attempt by the Senate is likely to set off a legal battle with the White House.