The House Judiciary Committee adopted a resolution Thursday outlining guidelines for a possible impeachment investigation of President Donald Trump, the most significant step yet taken by Democrats.

House Judiciary Committee Chairman Jerry Nadler, D-N.Y., said after the 24-17 party-line vote the guidelines will allow the panel to gather more information in a closed environment and allow the president’s lawyers to respond to public hearings with written statements. Committee lawyers would be able to question witnesses for an additional hour after any hearing.

Trump responded to the action with disdain, saying Democrats never did get over his election.

“Some call this process an impeachment inquiry. Some call it an impeachment investigation,” Nadler said during the announcement. “There is no legal difference between these terms, and I no longer care to argue about the nomenclature.”

The resolution was first announced Monday as a way to ensure the investigation was considered thorough and “effective.”

House Speaker Nancy Pelosi, D-Calif., has continued to push for other means of challenging Trump. She was asked about the resolution during her Thursday press conference, but declined to answer.

“I’m not answering anymore questions on this subject,” Pelosi said.

Nadler faced criticism committee ranking Republican Doug Collins, R-Ga., who said the resolution was unnecessary.

“The Judiciary Committee has become a giant Instagram filter,” Collins said.

Jerrold Nadler U.S. Rep. Jerrold Nadler (D-NY) listens during a House Rules Committee meeting at the U.S. Capitol on Feb. 25, 2019 in Washington, DC. Photo: Alex Wong/Getty Images