Facing the tough task of selling voters on an impeachment inquiry against President Donald Trump, Democrats struggled on Wednesday to craft a unified message explaining why he might deserve to be removed from office.

In the halls of Congress, on the campaign trail and on social media, many Democrats said Trump’s pressure on Ukraine’s president to investigate Democratic presidential front-runner Joe Biden was a clear-cut argument for an impeachment inquiry.

“This is about the future. This is about protecting America’s election and America’s national security. It is a matter I think that is not difficult to understand,” House of Representatives Majority Leader Steny Hoyer told reporters.

Democrats with military and intelligence backgrounds described the impeachment investigation as a duty, not a political fight they relished.

“In a district like mine, everything’s risky,” said US Representative Abigail Spanberger, a former CIA officer who flipped a Republican district in Virginia last year that had voted for Trump in 2016.

The allegations against Trump are “a significant threat to our national security,” she told constituents in a letter. “We an impeachment inquiry was not fully explained and could backfire, hurting Democrats in the 2020 elections.

US Representative Jeff Van Drew, a New Jersey Democrat, said he did not mind an investigation but was not ready to back impeachment. Drew said he had faced some pressure from colleagues to change his mind and get on board.

“It’s not pressure like someone putting you in a headlock, but it is pressure like ‘Gee, we are all doing this together, we all have the same message.’ And that’s not true,” he told reporters.

A House Democratic lawmaker who requested anonymity to discuss the handling of the inquiry said there was nervousness among more moderate members about whether Pelosi would hold a floor vote on impeachment, forcing them to go on the record.

“The party’s really operating on different tracks right now,and that can be confusing for the public,” said Colin Strother, a spokesperson for Representative Henry Cuellar’s re-election campaign in Texas.

“There’s definitely a gulf between the people that are ‘Impeach, no matter what,’ and the people that are ‘Follow the evidence.'”

Pelosi, who had resisted demands for an impeachment inquiry for months out of fear of the political repercussions, changed her mind after reports that Trump pressured Ukrainian President Volodymyr Zelenskiy in a July 25 telephone call to investigate Biden and his son Hunter, who had worked for a company drilling for gas in Ukraine.

A defiant Trump, whose administration released on Wednesday a summary of the call, denied any impropriety and said Democrats launched the impeachment inquiry “because they can’t beat us at the ballot.”

Public opinion polls indicate voters might not be ready for the impeachment of Trump.

A Reuters/Ipsos poll released on Tuesday, before Pelosi made the case for impeachment, found 37% of Americans thought Trump should be impeached, down from 41% in September. In public, Democrats largely brushed off concerns about the risks and said the issue was bigger than everyday politics.

“History will remember those who put politics aside at this time of crisis and treated it like the moral moment that it is,”said Democratic presidential candidate Cory Booker.

Most Democratic presidential contenders for the nomination to take on Trump in next year’s election support an impeachment inquiry, including Biden and US Senators Elizabeth Warren, Bernie Sanders, Kamala Harris and Amy Klobuchar.

“It is the constitutional responsibility of Congress to hold this man accountable,” Warren told reporters in Keene, New Hampshire.

Even some congressional Democrats facing tough re-election battles weighed in. In a tweet on Tuesday night, US Senator Doug Jones, who faces a difficult path to re-election in conservative Alabama, backed a congressional investigation of Trump and Ukraine.