The battle between Congressional Democrats and President Trump intensified Tuesday when former White House counsel Don McGahn refused to obey a subpoena to testify before the House Judiciary Committee.

When the hearing opened, the chair intended for McGahn remained empty. The hearing adjourned less than half an hour later.

Rep. Jerry Nadler (D-NY), the committee chairman, angered by McGahn’s defiance, stated the situation clearly in his opening remarks:

Mr. McGahn did not appear today because the president prevented it.

The Trump White House told McGahn not to appear before the committee, claiming he is exempt from testifying to Congress because he’s a former senior adviser to the president.

The president took it upon himself to intimidate a witness who has a legal obligation to be here today,” Nadler said. “This conduct is not remotely acceptable.”

McGahn was summoned to testify before the committee about what Nadler calls “a shocking pattern of obstruction of justice” by Trump, documented in special counsel Robert Mueller’s report.

“The President acted again and again — perhaps criminally — to protect himself from federal law enforcement,” Nadler wrote in a statement issued Monday. “Don McGahn personally witnessed the most egregious of these acts. President Trump knows this. He clearly does not want the American people to hear firsthand about his alleged misconduct….”

The “most egregious” act Nadler referred to was when Trump allegedly told McGahn to fire Mueller in the midst of his investigation — and McGahn refused.

Republicans dismissed the hearing as a stunt.

“Cameras love a spectacle, and Democrats covet the chance to rant against this administration,” said Rep. Douglas Collins (R-GA), the ranking minority member on the Judiciary Committee.

McGahn is now likely to face a contempt of Congress citation, unless “he does not immediately correct his mistake” of ignoring the subpoena, Nadler said, adding that the committee will eventually hear from McGahn, “even if we have to go to court to secure it.”

The entire episode boosts pressure on Democratic leaders to seek Trump’s impeachment.

House Speaker Nancy Pelosi (D-CA) “has scheduled a Democratic caucus meeting for Wednesday morning … according to two Democrats briefed on her plans,” reports the Washington Post. “Members expect the meeting will include a robust discussion of whether to launch an impeachment inquiry against Trump.”

Some members of the Judiciary committee, says CNN, “feel that Pelosi should be more aggressive and launch impeachment hearings that would make it easier to get information from the administration.”

As Nadler put it on Tuesday: “We will hold this president accountable, one way or the other.”