Former special counsel Robert Mueller says he would try to be an unappealing witness for Congress, promising he wouldn't say anything he hasn't said before.
House Democrats say that still sounds pretty good.
House Judiciary Committee Chairman Jerry Nadler, D-N.Y., reaffirmed on Wednesday that he continues to want Mueller to speak before his panel.
"Let's just say I'm confident he'll come in soon," Nadler told reporters.
He also emphasized that Mueller should testify in the open, not behind closed doors as the former special counsel had mused.
"We want him to testify openly. I think the American people need that. Frankly, I think that's his duty to the American people," Nadler said. "We'll make that happen."
Some key members of the Democratic majority believe that simply having Mueller describe his findings on TV — which could reach more Americans than his doorstop written report — would be worth doing for their own political reasons.
And there also are ways that members of Congress in both parties could try to learn new information and further their own ends in the event that Mueller appeared, even within the restrictions he said he would place on himself.
Here's some of what they might ask:
Did you obtain Trump's financial records?
There's nothing in the unredacted version of Mueller's report about Trump's tax returns or, more broadly, the finance and business-practice questions that Democrats want to make the focus of their own investigations into Trump.
Trump has said he assumes Mueller got his tax returns and investigators concluded all was copacetic. That was one basis for the broad way in which the president and his supporters have characterized Mueller's findings as an all-purpose inoculation — meaning, in their telling, any other investigations are baseless.
Only a few insiders know for sure what Mueller has and hasn't investigated. Mueller also has said that his report is his testimony.
So if he were to say, in so many words, to Nadler that the absence of a mention in the report suggests the absence of work by the special counsel's investigators, Democrats could then further justify the inquiries they have launched.
The House majority is trying to get Trump's tax records, accounting documents, business materials and other information with subpoenas and, in some cases, lawsuits.
The president has said his administration won't cooperate and is fighting some requests in court.
Why didn't you insist on an interview in person with Trump?
President Trump didn't agree to an interview with Mueller's investigators. Trump answered questions from the special counsel's office in writing — and even then, critics said, he barely participated.
Trump responded to questions by saying more than two dozen times that he didn't recall details about the subjects in question, including his own knowledge about Russia's interference in 2016 and the actions of his family or other close aides.
The benefit of the written responses was clear, from the perspective of Trump's lawyers: They feared the risks involved with putting a famously voluble Trump into a situation in which his statements might not have matched past ones and that Trump could fall into what his supporters warned might be a "perjury trap."
Why, though, did Mueller agree? The special counsel's report affirmed that he considered some of Trump's answers unsatisfactory and that investigators were frustrated by their inability to follow up with Trump to try to get more detail.
Ultimately, though, they did not press the issue.
Mueller's report explains that investigators didn't want to drag out their investigation with the legal fight that might have been required to compel testimony by Trump. The special counsel's office also said it believed it had established what it could have learned from Trump from other sources.
Members of Congress most likely want to ask Mueller to expand on that.
Why did you drop former FBI special agent Peter Strzok from your team?
Among the reasons Mueller very likely does not want to sit in the congressional spotlight, one of the strongest may be to avoid revisiting the subplot involving Strzok, a former counterintelligence specialist, and a former FBI lawyer named Lisa Page.
The two exchanged many messages on their official government phones that included a number of frank political opinions, some of which were critical of Trump, during the FBI's high-profile 2016 investigations. They have since said that they used the government phones to conceal an affair from their spouses.
When an internal investigation brought those to Mueller's attention, officials have said, the special counsel removed Strzok from the unit.
The bureau has been embarrassed by this episode and much of it has been hashed out in public, including in testimony for members of Congress by Page and Strzok themselves.
A Mueller hearing creates the opportunity for Republicans to ask Mueller himself why he considered the conduct unacceptable and, more broadly, for some of Mueller's critics to press him about other members of his team.
Trump and his supporters have charged that Mueller led a "witch hunt" pursued by a team of "angry Democrats" out to get the president based on nothing but partisan bias.
The leaders of the FBI and Justice Department — and Mueller — have defended the special counsel's office, but Mueller himself opened the door to a discussion about the quality of his personnel when he singled them out for praise last week in a subtle rebuke of all that earlier criticism.
Will you say now whether you believe Trump broke the law?
Mueller's report opened up a fracture between his view of his responsibilities and the opinion of his boss and sometime friend, Attorney General William Barr.
For Mueller, not only did the federal regulations prohibiting him from charging Trump mean he couldn't seek an indictment, but basic fairness meant Mueller couldn't say whether he thought one was necessary. He argued, in as many words, that saying so would amount to making a charge against Trump that the president wouldn't have an opportunity to contest at trial.
Barr, for his part, said that Mueller could have stated whether he believed Trump broke the law and an indictment was warranted, just not actually go on to prosecute the president.
With all that having developed since the reasoning Mueller detailed in his report, what, members might ask, does he think now? Has the attorney general's expression of his opinion put Mueller in a position — again, with the understanding that no charge could result — to now state whether he thinks Trump broke the law?
NPR congressional correspondent Susan Davis contributed to this report.