escalating impeachment probe !
PER CNN:
The subpoena came after the three committees leading the impeachment inquiry separately sent a letter Friday seeking documents from Vice President Mike Pence as part of their investigation into Trump and his conversation with the President of Ukraine.

Democrats have responded to White House stonewalling with contempt votes and lawsuits to pry loose the materials they were seeking. But they now appear to be taking a different tack with the Ukraine inquiry: arguing that a failure to cooperate will make their case that obstruction of justice occurred.