AP Photo From left House Speaker Nancy Pelosi, Chairwoman of the House Financial Services Committee Maxine Waters, D-Calif., Chairman of the House Foreign Affairs Committee Eliot Engel, D-N.Y., House Judiciary Committee Chairman Jerrold Nadler, D-N.Y., Chairwoman of the House Committee on Oversight and Reform Carolyn Maloney, D-N.Y., unveil articles of impeachment against President Donald Trump, during a news conference on Capitol Hill in Washington, Tuesday.

WASHINGTON (AP) — House Democrats announced two articles of impeachment against President Donald Trump on Tuesday, declaring his actions toward Ukraine “betrayed the nation” as they pushed toward historic proceedings that are certain to help define his presidency and shape the 2020 election.

The specific charges aimed at removing the 45th president of the U.S.: abuse of power and obstruction of Congress.

Speaker Nancy Pelosi, flanked by the chairmen of impeachment inquiry committees at the U.S. Capitol, said they were upholding their solemn oath to defend the Constitution. Trump responded angrily on Twitter: “WITCH HUNT!”

Voting is expected in a matter of days by the Judiciary Committee, and by Christmas in the full House. The charges, if approved, would then be sent to the Senate, where the Republican majority would be unlikely to convict Trump, but not without a potentially bitter trial just as voters in Iowa and other early presidential primary states begin making their choices.

In the formal articles announced Tuesday, the Democrats said Trump enlisted a foreign power in “corrupting” the U.S. election process and endangered national security by asking Ukraine to investigate his political rivals, including Democrat Joe Biden, while withholding U.S. military aid as leverage. That benefited Russia over the U.S. as America’s ally fought Russian aggression, the Democrats said.

Trump then obstructed Congress by ordering current and former officials to defy House subpoenas for testimony and by blocking access to documents, the charges say.

By his conduct, Trump “demonstrated he will remain a threat to national security and the Constitution if allowed to remain in office, “ the nine-page impeachment resolution says.

“If we did not hold him accountable, he would continue to undermine our election,” Pelosi said later at a forum sponsored by Politico. “Nothing less is at stake than the central point of our democracy – a free and fair election.”

After decrying the Democrats’ announcement, Trump headed to Pennsylvania for a reelection campaign rally.

First, he tweeted that to impeach a president “who has done NOTHING wrong, is sheer Political Madness.”