House Democrats’ formal impeachment inquiry is 10 days old. And as of late Thursday, it had already uncovered evidence that multiple top U.S. diplomats understood there to be a quid pro quo with regard to Ukraine launching investigations that could help President Trump politically.

The rapidity of this and other disclosures is particularly ominous for the White House. And it suggests there will be no shortage of leads in an investigation that increasingly holds promise for Democrats.

The big news late Thursday was text messages turned over by the recently departed U.S. envoy to Ukraine, Kurt Volker. The texts show that he and another diplomat, Bill Taylor, understood the White House to be requiring Ukraine to launch the investigations in exchange for either a meeting with Trump, military aid or both.

Volker at one point even referenced the White House having conveyed this message.

“Heard from White House,” Volker wrote. “Assuming [Ukraine] President Z[elensky] convinces trump he will investigate / ‘get to the bottom of what happened’ in 2016, we will nail down date for visit to Washington.”

In a separate exchange with a top aide to Zelensky, Andriy Yermak, Yermak references scheduling the meeting before Ukraine will announce the investigations.

And yet another text shows Taylor believed hundreds of millions of dollars in military aid that was being withheld might also have been a quid pro quo — and that he understood the payoff to not just be investigations, but political help for Trump.

“I think it’s crazy to withhold security assistance for help with a political campaign,” Taylor wrote.

Gordon Sondland, the U.S. ambassador to the European Union, then responded with a very carefully worded text denying the quid pro quo and suggesting they speak by phone — as if he knew the contents of texts would one day be part of just such an inquiry.

Republicans have said that Volker’s actual deposition Thursday — what he said in addition to the text messages he turned over — is actually favorable to Trump and damaging to the impeachment inquiry. We’ll have to see.

But at the very least, these texts suggest there was considerable consternation behind the scenes about how the situation was being handled, and they indicate a belief among top stakeholders that there was indeed a quid pro quo that was geared toward helping Trump politically.

This evidence bolsters the complaint of a still-unknown whistleblower who cited “more than half a dozen” people as providing evidence to them. The whistleblower also said there were “more than a dozen” people on the phone call between Trump and Zelensky on July 25, during which Trump explicitly requested the investigations after suggestively noting how good the United States had been to Ukraine. And then we have the removal of the former U.S. ambassador to Ukraine, Marie Yovanovitch, whom the Wall Street Journal now reports Trump ordered removed.

That’s a whole lot of potential witnesses and angles. And after just one major figure is deposed, we already have significant new evidence to throw on top of the whistleblower complaint and the rough transcript of the Trump-Zelensky call.

The White House and State Department are apparently going to make it difficult to talk to many of those witnesses. But Volker’s rapid departure from the special envoy post and disclosures suggest there might be something of a siege mentality — in which individuals involved who know stuff will come out, and they’d rather be on the front end of it.

Volker, in particular, could have been vilified as having been involved in a quid pro quo scenario and not stopped it at the time. But now he has left his position, allowed himself to be deposed — even as the State Department is preventing its employees from participating — and proactively handed over these text messages. If you’re someone else involved in this, you have to wonder if you might also want to get out in front of this story, for fear that others could beat you to the punch.

Democrats have insisted they want to conduct an expeditious inquiry. That’s looking increasingly unlikely — but for reasons that they’re probably okay with.

A few important questions:

  1. How many other people felt there was an explicit quid pro quo?
  2. Who in the White House did Volker hear from before he conveyed the apparent quid pro quo involving the meeting?
  3. Will Taylor turn into the key witness that Trump opponents hope he might? (His inquiries of Sondland almost make it sound like he was collecting evidence or at least covering himself.)
  4. How does Sondland account for what appear to be his efforts to avoid leaving records of his interactions with Taylor, along with his carefully worded response?
  5. How much more is there to the Yovanovitch story?

There’s a lot there, and it’s starting to feel like this has really only scratched the surface.