Former Trump campaign chair Paul Manafort testified before the Senate Intelligence Committee in closed session. The transcript of that session isn’t being shared.

Lawyers working with a team led by special counsel Robert Mueller approached the Senate intelligence committee this summer with a request: They wanted the transcript of an interview Senate staff had conducted with former Trump campaign chairman Paul Manafort.

But they were blocked. Manafort's lawyers said they had not authorized Mueller's legal team to access the interview transcript under the agreement with the committee, even though Mueller's attorneys said they had been given permission. 

There’s a central problem with the investigations into Russia that are underway in the House and Senate: they don’t necessarily want to find anything wrong. Both houses are more interested in showing that they are investigating than they are in finding anything. They recognize the public demand is there to look into the connections between Trump and Russia, but also worry that finding anything would interfere with Republicans’ best opportunities to pass tax bills and other items on their agenda.

On the other hand, the investigation under special counsel Robert Mueller is all about charges. What little we know about the state of Mueller’s investigation comes from those times when its requests have gone public or when information has leaked. If Mueller’s investigation fails to produce indictments, odds are it will be folded up quietly, with the grand jury sworn to secrecy and little of the information uncovered ever being revealed to the public. 

The basic conflict between Mueller’s team and the congressional investigations is starting to generate friction that goes beyond not sharing Manafort’s Senate statements. And the conflicts aren’t limited to Congress vs. Mueller. The different congressional investigations are also competing with each other for time in the spotlight.

In some cases, lawmakers asked their staffs to hold off on scheduling high-profile interviews while they were gone for the August recess — only to get annoyed when another committee then swooped in and scheduled their own interviews in the interim.

With the three congressional committees fighting over air time and Mueller simply trying to amass evidence, there are inevitable conflicts.

That could mean early signs of tension between the special counsel and the Hill become more pronounced as the competing congressional inquiries try to determine whether there was any collusion and as Mueller potentially pursues criminal charges.

That’s on top of issues like those on the House side, where Rep. Devin Nunes is threatening to step back in from his apparently temporary recusal, and other Republicans on the committee seem interested in anything but Trump–Russia. Previous sessions have seen questions divided between Democrats attempting to advance the investigation the committee is supposedly carrying out, while Republicans use their air time to attack everyone from Obama to Hillary—and sidetrack the committee down a long, fruitless, evidence-free trip into “unmasking.”

Because the congressional committees are more interested in being seen to investigate than actually uncovering evidence, there’s also the possibility that they could end up engaging in agreements or protections that make it difficult for Mueller to conduct his investigation.

Lawmakers … have instead moved forward with private witness interviews, including Donald Trump Jr., who is expected to head to the Senate intelligence committee this month, sources say, and is expected to meet with the Senate judiciary committee as well.

In the Iran-Contra investigation, immunity granted to witnesses allowed insiders like John Poindexter and Oliver North to avoid paying for their crimes. Courts ruled that even though the independent counsel didn’t depend on testimony that was presented before Congress and the grand jury was ordered to disregard anything they might have heard from congressional testimony, figures like North couldn’t be given a fair trial. Any form of congressional immunity granted in the current investigation risks the same issues.

Similar issues affect even the simple collection of evidence.

On Capitol Hill, the closed-door transcribed interviews are causing complications in the delicate relationship with the special counsel.

That can mean not just transcripts of testimony, but other documents presented or discussed during such testimony.

As a result of the dispute, the committee hasn't turned over any documents and the matter is still under discussion, sources say.

While the intentional slowdowns that took place in earlier congressional investigations were done with the purpose of protecting Trump, at this point Congress might seek to expand their investigations—for the same reason. Because the more they investigate, the more things they can entangle, making it difficult for the special counsel.