WASHINGTON — House Speaker Nancy Pelosi may have created a "foregone conclusion" problem for Democrats.

The California lawmaker declared President Donald Trump guilty Tuesday as she told colleagues that the House should complete a formal investigation into his conduct in speedy fashion.

Trump committed a "betrayal" of his oath of office, national security and election integrity by urging Ukraine's president to investigate 2020 Democratic presidential candidate Joe Biden and his son Hunter, she said in a closed-door meeting of the Democratic caucus. A summary of a call between Trump and Russian President Volodomyr Zelenskiy released by the White House on Wednesday confirmed that the request happened at the same time Trump was withholding aid to Ukraine.

Trump's solicitation of foreign help to hurt a political opponent — again — became a tipping point for many Democrats, including Pelosi.

Now, the speaker seems to have already concluded that Trump betrayed his country.

But she appeared to betray something about motives having little to do with the principles of justice, due process and the rule of law that the president's critics fault him for failing to honor or the 24-hour diner menu of impeachment options he has given Democrats since he took office.

"If none of that had occurred, what has happened this week is grievous and serious with our Constitution. And so, we must — it is understandable to the public. It has clarity in terms of what he did," she told Democrats, according to excerpts of her remarks provided to NBC by a senior Democratic aide who was in the room. "Right now, we must strike while the iron is hot."

In other words, don't bore the people with a trial; get to the verdict while they're still paying attention.

Democrats are reluctant to criticize Pelosi publicly — both in general, and particularly amid an impeachment frenzy in their party — but they fret privately about the prospects of how their party will handle Republican questions about the Bidens during an impeachment inquiry, whether Trump would be more likely to pay a price for seeking political help from Ukraine than receiving assistance from Russia during the 2016 election, and what the plan is for convincing voters that impeaching him is simply the right thing to do.

Chris Kofinis, a Democratic strategist who has worked on presidential campaigns and conducts research on political messaging and public opinion, stopped short of critiquing Pelosi's tack. But he acknowledged in a telephone interview with NBC News that it may not be as obvious to voters as it seems to Democratic lawmakers that Trump's conduct merits impeachment.

"Given the historic nature of this action, there’s going to be a significant responsibility on us to explain to the American people exactly what he did wrong,” Kofinis said. “We want to make it clear that he is guilty. What we want to do is avoid making him a martyr.”

The cautious Pelosi, who once warned against basing impeachment decisions on political calculations, has been replaced by a version determined to lead her party's charge into a constitutional showdown with Trump rather than get trampled by it. In doing so, she seemed to abandon the solemnity she had observed for eight months as rank-and-file liberals clamored for blood, and grab the biggest torch she could find.

But in political terms, the House's target audience in this process is still swing voters — the set that could either sway congressional Republicans on impeachment (unlikely) or punish the GOP at the ballot box. But there's a pretty big risk in a scenario that some see as Democrats' bum-rushing Trump for partisan gain rather than seeking justice for the public.

"If the president did this, it’s an impeachable offense and everyone should take it seriously,” said Kristen Hawn, a Democratic consultant who has long worked with moderate Blue Dog lawmakers. But, Hawn added, there might be a better way to pursue the facts.

“Members should establish a bipartisan select committee to look into what the president did or didn’t do with regard to Ukraine,” she said.

Pelosi declined to take that step Tuesday.

It has been all but inevitable since at least the release of former special counsel Robert Mueller's report, which detailed evidence he found that Trump may have obstructed justice, that the House would move to impeach Trump. The manner and timing have been more in doubt.

Ron Bonjean, a founder of the public relations firm Rokk Solutions and a House GOP aide during the impeachment of President Bill Clinton, said impeachment will now overshadow everything else Pelosi is trying to get done — and to her disadvantage.

“By endorsing an official impeachment inquiry, Speaker Pelosi has greatly risked turning the Democratic agenda into a singular focus of removing President Trump from office,” he said. “She has allowed President Trump and Republicans to call out the Democratic leadership for focusing on partisanship instead of creating bipartisan solutions, thus handing them political gift for the 2020 elections.”

But Pelosi has opted not to waste what Democrats describe as momentum for impeachment.

No one really knows how the politics of impeachment will ultimately play out. It is highly unlikely that the Senate will vote to remove Trump, and it is unclear what effect, if any, a House vote to impeach him would have on his re-election prospects. Even as Trump's campaign manager, Brad Parscale, boasted that it would backfire on Democrats and end in a "landslide victory" for Trump in 2020, there was some concern about the potential impact in the president's inner circle.

Perhaps the substance will matter more than the politics.

But Pelosi is staking herself to the politics right now. And her cart-before-the-horse judgment looked likely to make it harder for Democrats to defend themselves against Trump's charge that they are engaged in a "witch hunt" — even if the evidence against him proves to demand impeachment, as many Democrats now contend that it does.

The process might have been perceived by the public as more legitimate if Pelosi had framed the House's upcoming work as an investigation rather than an "impeachment inquiry" and if she hadn't reached a "foregone conclusion" about whether his conduct rises to the level of impeachment, said one House Democrat who spoke to NBC on the condition of anonymity, out of fear of reprisal from Pelosi.

As recently as Monday afternoon, Democratic lawmakers and aides were predicting that there would be a sea change in impeachment sentiment if the director of national intelligence refused to provide the full whistleblower complaint on Trump's interactions with Ukraine during a House Intelligence Committee hearing Thursday. By Tuesday morning, the tide already had turned in favor of moving on Trump before the hearing — a reflection in part of a belief that what he had already acknowledged publicly about his contacts with Ukraine was bad enough without whatever lay beneath the surface in the complaint.

The Democrats, after all, are still smarting from Trump's public courting of Russia's help — which he got — in the last election. They think that was an America-second, Trump-first move.

Now, the Trump administration is expected to release at least some of the whistleblower complaint, in addition to the transcript.

Pelosi told Democrats to ignore the debate over whether there was an explicitly stated "quid pro quo" in the president withholding aid for Ukraine while he and his team were pushing for an investigation into Hunter Biden.

"Don't get caught in the trap of, 'Oh, there is no quid pro quo,'" she said. "No, he asked for assistance from the foreign government. That is wrong."

That is, his actions are impeachable in her view even if they don't involve the legal definition of extortion or bribery.

Moments later, she referred to Trump's "betrayal of the Constitution" as her rationale for proceeding with the impeachment inquiry.

In the Federalist Papers, Alexander Hamilton defined "high crimes and misdemeanors" — one category of misdeeds for which a president may be impeached — as "those offences which proceed from the misconduct of public men, or in other words from the abuse or violation of some public trust."

Pelosi's term — "betrayal" — is perhaps a harsher substitute for "violation." But her construction is parallel to the "violation of some public trust" that Hamilton foresaw.

Still, in the end, it might ultimately be most important to ensure the public doesn't view the process as a witch trial.

The lawmaker who spoke to NBC on the condition of anonymity worried that crucial swing voters are not particularly tuned into the Ukraine story line, and will see the impeachment now as partisan warfare.

The rush to impeach, this lawmaker said, is "silly momentum."