"John Bolton should testify," said Sen. Mark Warner (D-VA).
"The only reason the GOP controlled Senate would refuse to subpoena John Bolton to testify is because they are afraid of what he will tell the American people," said Rep. Ted Lieu (D-CA).
Democrats believe Bolton could have crucial information about how President Trump dealt with Ukraine, as Democrats charge he withheld military aid and pressed Ukraine to announce investigations which could benefit the President's 2020 re-election bid.
“Bolton is an important witness to misconduct involving Ukraine that he called a 'drug deal,'” said House Intelligence Committee Chairman Rep. Adam Schiff (D-CA). “The cover up must end.”
“The President & Sen. McConnell have run out of excuses,” House Speaker Nancy Pelosi tweeted. “They must allow key witnesses to testify, and produce the documents Trump has blocked, so Americans can see the facts for themselves.”
In the Senate, Democrats have been trying to put pressure on a small group of Republicans, in hopes that they will break with their leadership, and demand testimony and documents not only from Bolton, but from other White House officials who defied subpoenas from the House.
“Regardless of what Bolton’s testimony might be, I want to hear from him and review his documents,” said Sen. Doug Jones (D-AL).
“We are asking only that the President’s men, his top advisers, tell their side of the story,” said Senate Democratic Leader Charles Schumer.
Among those Democrats have tried to specifically target over trial witnesses are Sen. Lisa Murkowski (R-AK), Sen. Cory Gardner (R-CO), Sen. Mitt Romney (R-UT), and Sen. Susan Collins (R-ME).
The Bolton statement comes as House Democrats are still holding on to the actual impeachment articles, as a Senate trial will not be triggered until those papers are delivered by the House.
At this point, Democrats seem ready to wait - how long remains unclear.