Former special counsel Robert Mueller has agreed to testify publicly before the House Intelligence and Judiciary committees pursuant to a subpoena on July 17, Chairmen Adam Schiff (D-Calif.) and Jerry Nadler (D-N.Y.) announced Tuesday evening. The testimonies will be "back to back," but separate, according to Schiff.

Why it matters: Mueller previously said he preferred not to testify and that his 400-page report would function as his testimony. After weeks of negotiations between the former special counsel's team and House Democrats, a subpoena is what ultimately broke the deadlock.

“Pursuant to subpoenas issued by the House Judiciary and House Permanent Select Committee on Intelligence tonight, Special Counsel Robert S. Mueller III has agreed to testify before both Committees on July 17 in open session.

“Americans have demanded to hear directly from the Special Counsel so they can understand what he and his team examined, uncovered and determined about Russia’s attack on our democracy, the Trump campaign’s acceptance and use of that help, and President Trump and his associates' obstruction of the investigation into that attack.

“We look forward to hearing his testimony, as do all Americans.”

— Chairmen Nadler and Schiff

What he's saying: Though not explicitly a response to the announcement, President Trump tweeted after the news was announced, "Presidential Harassment!"

The big picture: Mueller's public testimony has long been the white whale for Democratic leaders who have staved off calls to impeach Trump until they can further "educate the public" on the contents of the special counsel's report. Public readings of the report and expert testimony have failed to garner the same attention that a high-profile hearing with one of the most mysterious figures of the last two years of the Trump presidency undoubtedly will.

Flashback: On May 29, Mueller gave his first and only public statement since his appointment in 2017. Here's what he said regarding any potential testimony:

There has been discussion about an appearance before Congress. Any testimony from this office would not go beyond our report. It contains our findings and analysis, and the reasons for the decisions we made. We chose those words carefully, and the work speaks for itself.

The report is my testimony. I would not provide information beyond that which is already public in any appearance before Congress.

The bottom line: Mueller's testimony will not be a bombshell for anyone who has read his report.

But hearing him answer questions in a televised setting about the explosive details of the Trump campaign's willingness to accept Russian help, as well as a verbal recounting of the president's alleged obstruction of justice, could have a tremendous effect on public opinion.

in a televised setting about the explosive details of the Trump campaign's willingness to accept Russian help, as well as a verbal recounting of the president's alleged obstruction of justice, could have a tremendous effect on public opinion. It's also likely to infuriate Trump.

This article has been updated to include Trump's tweet and Schiff's comments on Mueller's reluctance to testify.

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