WASHINGTON (AP) – House Speaker Nancy Pelosi launched a formal impeachment inquiry against President Donald Trump on Tuesday, Sept. 25, yielding to mounting pressure from fellow Democrats and plunging a deeply divided nation into an election year clash between Congress and the commander in chief.

The probe focuses partly on whether Trump abused his presidential powers and sought help from a foreign government to undermine Democratic foe Joe Biden and help his own re-election. Pelosi said such actions would mark a “betrayal of his oath of office” and declared: “No one is above the law.”

The inquiry, after mnths of investigations by House Democrats of the Trump administration, sets up the party’s most direct and consequential confrontation with the president, injects deep uncertainty into the 2020 election campaign and tests anew the nation’s constitutional system of checks and balances.

Pelosi’s brief statement, delivered without dramatic flourish but in the framework of a constitutional crisis, capped a frenetic weeklong stretch on Capitol Hill as details of a classified whistleblower complaint about Trump burst into the open and momentum shifted to ward an impeachment probe.

For months, the Democratic leader has tried calming the push for impeachment, saying the House must investigate the facts and let the public decide. The new drive was led by a group of moderate Democratic lawmakers from political swing districts, amny of them with national security backgrounds and serving in Congress for the first time. The freshmen, who largely represent districts previously held by Republicans where Trump is popular, risk their own re-elections but say they could no longer stand idle. Amplifying their call were longtime leaders, including Rep. John Lewis of Georgia, the civil rights icon often considered the conscience of House Democrats.

The Issue

At issue are Trump’s actions with Ukraine. In a summer phone call with Ukrainian President Volodymyr Zelenskiy, he is said to have asked for help investigating former Vice President Biden and his son Hunter. In the days before the call, Trump ordered advisers to freeze $400 millinion in military aid for Ukraine – prompting speculation that he was holding out the money as leverage for information on the Bidens. Trump has denied that charge, but acknowledged he blocked the funds, later released.

Biden said Tuesday, before Pelosi’s announcement, that if Trump does not cooperate with lawmakers’ demands for documents and testimony in its investigations, the president “will leave Congress … with no choice but to initiate impeachment.” He said that would be a tragedy of Trump’s “own making.”

The Trump-Ukraine phone call is part of the whistleblower’s complaint, though the administration has blocked Congress from getting other details of the report, citing presidential privilege.

Trump has authorized the release of a transcript of the call, which was made public on Wednesday.

“You will see it was a very friendly and totally appropriate call,” Trump said.

Trump has sought to implicate Biden and his son in the kind of corruption that has long plagued Ukraine. Hunter Biden served on the board of a Ukrainian gas company at the same time his father was leadeing the Obama administration’s diplomatic dealings with Kyiv. Though the timing raised concerns among anti-corruption advocates, there has been no evidence of wrongdoing by either the former vice president or his son.

GOP Response

After Pelosi’s announcement, the president and his campaign team quickly released a series of tweets attacking Democrats, including a video of presidential critics like the speaker and Rep. Ilhan Omar discussing impeachment. It concluded: “While Democrats ‘Sole Focus’ is fighting Trump, President Trump is fighting for you.”

Senate Majority Leader Mitch McConnell said Pelosi’s well-known “efforts to restrain her far-left conference have finally crumbled.”

Pelosi has for months resisted calls for impeachment from her restive caucus, warning that it would backfire against the party unless there was a ground swell of public support. That groundswell hasn’t occurred, but some of more centrist lawmakers are facing new pressure back home for not having acted on impeachment.

While Pelosi’s announcement adds weight to the work being done on the oversight committees, the next steps are likely to resemble the past several months of hearing and legal battles – except with the possibility of actual impeachment votes.

On Wednesday, the House passed a resolution insisting the Trump administration turn over to Congress the whistleblower’s complaint. The Senate, in a rare bipartisan moment, approved a similar resolution.

The lawyer for the whistleblower, who is still anonymous, released a statement saying he had asked Trump’s director of national intelligence to turn over the complaint to House committees and asking guidance to permit the whistleblowers to meet with lawmakers.