Pennsylvania’s two U.S. senators fell on opposite, and predictable, sides of the impeachment debate Wednesday, as the White House released a memo showing President Donald Trump pressured Ukraine’s leader on a July phone call to investigate a rival in the 2020 presidential campaign.

Republican Sen. Pat Toomey said Trump’s conversation was “inappropriate” but did not “rise to the level of an impeachable offense.”

If the House were to vote to impeach Trump, the outcome of a trial in the Senate may well hinge on votes cast by swing-state Republicans like Toomey. The GOP has majority control of the chamber.

Democrat Bob Casey threw his support behind the impeachment inquiry announced Tuesday by House Speaker Nancy Pelosi, saying Trump’s conduct was a “textbook case of abuse of power."

“In order to hold President Trump fully accountable, I support a formal impeachment inquiry in the House of Representatives,” Casey said in a statement. He said his concerns had grown in recent months as he “thoroughly” reviewed special counsel Robert Mueller’s report on Russian interference in the 2016 election and Trump’s possible obstruction of that probe.

“President Trump’s most recent actions with regard to Ukraine have created new urgency to take action,” Casey said. The Democrat, who was reelected to a third six-year term last year, added that Trump’s actions in the Russia investigation and in the Ukraine imbroglio meet the constitutional threshold of “high crimes and misdemeanors” that the Senate would consider in an impeachment trial.

More than 200 House Democrats have said they support an impeachment inquiry, including nearly all Philadelphia-area Democratic representatives. Rep. Jeff Van Drew, of Cape May County, remains a holdout.

The memo released by the White House showed Trump asked Ukraine President Volodymyr Zelensky on a July phone call to work with his personal lawyer Rudy Giuliani and Attorney General William Barr to investigate former Vice President Joe Biden and Biden’s son, Hunter. Biden is a leading contender for the Democratic presidential nomination next year.

Trump and his allies have argued, without evidence, that Biden as vice president sought to oust a Ukrainian prosecutor in an effort to protect his son, who sat on the board of a Ukrainian gas company that had drawn scrutiny.

House Democrats are investigating, in part, whether Trump held up nearly $400 million in military aid to push the Ukrainians to dig up dirt on the Bidens. The Republican president has acknowledged delaying the aid — which had been approved by Congress — but said he’d done so out of concern that other countries weren’t contributing their fair share.

Trump said at a news conference at the United Nations on Wednesday that he didn’t “threaten anybody.”

“It’s all a hoax, folks,” he said.

Pelosi said Wednesday that the memo confirmed Trump “engaged in behavior that undermines the integrity of our elections, the dignity of the office he holds and our national security.”

Toomey said the memo revealed no “quid pro quo” with regard to U.S. military aid and a Biden probe.

“While the conversation reported in the memorandum relating to alleged Ukrainian corruption and Vice President Biden’s son was inappropriate, it does not rise to the level of an impeachable offense,” he said in a statement.

Trump’s phone call with Zelensky is reportedly one component of a complaint filed by a whistle-blower in the intelligence community. The complaint was provided to Congress on Wednesday, and House Intelligence Committee Chairman Adam Schiff called its allegations “deeply disturbing” and “very credible.”

Casey’s statement marked a change from his previous position on impeachment.

After Mueller released his report in May, Casey declined to say whether the House should begin impeachment proceedings. “As a senator who would have the solemn responsibility of weighing evidence during an impeachment trial, I will not render a judgment as to whether impeachment proceedings should begin or how I would vote before hearing all the evidence,” Casey said at the time.

Mueller found that there was insufficient evidence to establish that the Trump campaign conspired with Russia, but documented several instances in which the president may have obstructed the investigation.

Should there be a Senate trial on impeachment, Casey said Wednesday he would “keep an open mind."

“However, at this time, I cannot ignore the public evidence which has confronted all of us,” he said.