(Elyse Samuels,Jenny Starrs/The Washington Post)

There have been other moments in the lengthy investigation of Russian government interference in the 2016 presidential election that have registered on the legal and political Richter scales, but none with the power and explosiveness of the email chain involving Donald Trump Jr. that became public Tuesday.

The emails between President Trump’s oldest son and an intermediary for the Russians provide the clearest indication to date that Trump campaign officials and family members were at least prepared to do business with a foreign adversary in the mutual goal of taking down Hillary Clinton.

No one should presume to draw definitive conclusions from the contents of the emails as to possible jeopardy for Trump Jr.; where the overall investigation, which includes various threads, is heading; or most specifically how it will end. That remains the purview of special counsel Robert S. Mueller III and investigators for the House and Senate intelligence committees. But in terms of public disclosures, what came out Tuesday was as stunning as anything to date, described by people closely watching on the outside as both breathtaking and surreal.

For those who had grown tired of the Russia issue or who believed it was losing potency or who thought the biggest surprises were in the past, Tuesday’s revelations provided dramatic proof that the investigation is alive with no end in sight. And at a minimum, the information in the emails demolishes the president’s claim, made as recently as last week, that “nobody really knows” whether the Russians meddled in the U.S. election and, if they did, whether they did so with the intent of helping him and hurting Clinton.

Sen. Mark R. Warner (D-Va.), vice chairman of the Senate Intelligence Committee, told reporters on Capitol Hill that the contents of the emails showed clearly the Russians’ desire to interfere in the election with the intent of hampering Clinton and that, crucially, officials in the Trump operation “were aware of that.” He declined to speculate about how high up the chain of command that awareness might go.

Donald Trump Jr. with his father after a debate against Democratic nominee Hillary Clinton at Hofstra University in Hempstead, N.Y., last fall. (Mike Segar/Reuters)

The emails read like something out of a cheap spy thriller — or perhaps even a falsified document designed to lure and entrap a willing but unsuspecting victim. They also happen to lay out information that is transparently damaging and that undermines those who have dismissed suggestions of possible collusion or cooperation between Trump associates and the Russians as fanciful or deliberately misleading.

The language in the messages to Donald Trump Jr. is conspiratorial and explicit. The president’s son was offered “official documents” that would “incriminate Hillary” and that would be “very useful to your father.” Trump Jr. was also informed in the emails that the information being offered was “part of Russia and its government’s support for Mr. Trump.”

Rather than setting off alarms within the Trump operation, the emails were gratefully received. “I love it,” Trump Jr. responded at one point. He agreed to set up a meeting to hear the information and said he would bring along Paul Manafort, at the time the Trump campaign’s chairman, and Jared Kushner, the president’s son-in-law and now a senior White House adviser with an expansive portfolio and great power. That meeting took place on June 9, 2016.

Trump’s son said Tuesday that he was releasing the emails in the interest of transparency, but that decision came after the New York Times informed him that its reporters had the contents and were preparing to publish. Day by day, thanks to the Times’ reporting, Trump Jr. has been dissembling about how and why a meeting with a Russian lawyer came about.

When reporters from the Times first approached him about the meeting, he said it was primarily about adoption, then later he conceded that he had been told that the purpose was to present damaging information about Clinton. Now it turns out there was an explicit connection to the Russian government. His rapidly changing explanations left White House chief of staff Reince Priebus hung out to dry with his comment Sunday that the meeting was about adoption.

Trump Jr. has been defiant in defense. He said that nothing untoward came from the meeting, that the Russian lawyer offered nothing credible about Clinton and that the discussion moved on to the Magnitsky Act, passed in 2012 to sanction Russian human rights abusers, which in turn prompted the Russians to shut down American adoptions of Russian children. He also tweeted that he was hardly the first campaign operative to be open to damaging information about an opponent.

Still, much isn’t known about what happened subsequently, if anything. Given that the meeting took place in June 2016, at the front end of the general-election campaign, is it credible that this was the last communication between the Russians and people in the orbit of the Trump campaign?

Was this a single entreaty that led to nothing and was shut off, or is there something more that could come out in the future? Two things are known. More than a month later, WikiLeaks dropped a batch of emails hacked from the Democratic National Committee, and days after that, then-candidate Trump called on the Russians to hack into Clinton’s private emails and release them to the public.

The president, whose patience for the Russia investigation expired long ago and who now must recognize that it will stay with him and his administration for the foreseeable future, offered only the briefest of comments in reaction to the news. He called his son “a high-quality person” and said he applauded him for transparency. No one else was holding back as the revelations lit up Twitter and stoked endless rounds of discussion, analysis and speculation on cable television.

Among those trying to look the other way at this awkward moment was Vice President Pence. Marc Lotter, the vice president’s press secretary, said in a statement that Pence remains focused on the president’s agenda, adding, “He is not focused on stories about the campaign, particularly stories about the time before he joined the ticket.” Pence was not brought on as Trump’s running mate until a month after the meeting in question.

It is by now a cliche to note that the Russia investigation not only hangs over the Trump presidency and his White House but that it also runs smack against efforts by Republicans to move ahead on their and the president’s agenda. For Republicans, it is the most troubling of revelations at the worst of moments, as Senate Majority Leader Mitch McConnell (R-Ky.) attempts to pass a health-care bill and as other legislation remains clogged in the pipeline.

Republicans can only wait as they watch the Russian front with trepidation. They hope that the eventual conclusion of the investigations will be exculpatory at best and murky at worst: a finding of clear Russian interference with motivation to help the president, but no definite connections among the various dots that hint at — but have not yet proved — collusion.

After what landed with such force Tuesday, however, they know there could be more damaging revelations to come. They are caught in a limbo. Whatever private fears they have, they are still attempting to remain publicly loyal to a president whose loyalty in return can never be taken for granted. Yet they know that their own political futures could hinge on what happens in the Russia investigation in the coming months.

Mueller’s investigation appears to be wide-ranging, from possible abuse of power by the president in his attempts to limit the probe, to questions about cooperation or collusion between Trump associates and the Russians, to financial dealings by officials that have raised questions in the past. No one knows what else, if anything, he and his team are digging into. But the emails that were released Tuesday make for a provocative addition to that already heavy load, one that will keep the White House and its allies on edge for some time to come.