House Speaker Nancy Pelosi kicked off the debate on the articles of impeachment against President Donald Trump on Wednesday, saying he “gave us no choice” but to charge him with abuse of power and obstruction of Congress in her opening remarks.

“If we do not act now, we would be derelict in our duty,” Pelosi said. “It is tragic that the President’s reckless actions make impeachment necessary. He gave us no choice.”

“What we are discussing today is the established fact that the President violated the Constitution,” she continued. “It is a matter of fact that the President is an ongoing threat to our national security and the integrity of our elections, the basis of our democracy.”

Dressed in all black, Pelosi also recited the Pledge of Allegiance ahead of the debate, putting an emphasis on the part of the pledge that says, “to the republic, for which it stands.”

“A republic, if we can keep it,” she said, repeating a quote from Benjamin Franklin. Her remarks earned her a standing ovation.

The House officially began six hours of debate on the two articles of impeachment Wednesday afternoon. A vote on each article is scheduled to take place Wednesday evening. Trump, who is set to become the third U.S. president to be impeached after Wednesday’s vote, spoke out against the proceedings on Twitter, calling them “atrocious lies by the radical left.”

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Write to Mahita Gajanan at mahita.gajanan@time.com.