What is going on here? Why is the presumptive Democratic nominee for president so eager to testify about a pair of topics that may be the two biggest threats to her candidacy, and why did Gowdy not schedule an immediate hearing—instead resisting the offer for weeks? After all, Clinton's last congressional appearance on Benghazi, shortly before she left office in January 2013, produced a moment that Republican ad-makers and conservative TV hosts have replayed countless times since. ("What difference, at this point, does it make?" a frustrated Clinton snapped at Senator Ron Johnson of Wisconsin back then.)

Let's take Gowdy first. From the moment Speaker John Boehner selected him to lead the select committee nearly a year ago, the third-term conservative and former federal prosecutor has been out to prove that this inquiry is a Serious Investigation. The burden was high to begin with: After a half-dozen inquiries by congressional committees into the attack that killed four Americans, including Ambassador Christopher Stevens, Democrats considered the matter closed. They denounced the new panel as a partisan exercise aimed both at damaging their party in the 2014 and Clinton in 2016.

Gowdy's approach was to be the opposite of Darrell Issa, the attention-grabbing former chairman of the Oversight Committee whose over-the-top style frequently backfired, to the annoyance of fellow House Republicans. Gowdy took his time getting the committee set up and made a point of holding few public hearings, arguing that closed-door depositions were often more effective than the spectacle of televised testimony. Democrats on the panel went along with Gowdy for a time, but as the investigation continued, they have increasingly accused Republicans of dragging it out with the 2016 election in mind.

The disclosure earlier this year that Clinton conducted State Department business on a private email account rejuvenated the investigation. It was the committee's request for Clinton's Benghazi-related correspondence that helped bring the news to light. And Clinton's admission that she deleted her emails after choosing which ones to turn over to the State Department prompted a whole new line of questioning from Gowdy, who sought access to her server to determine if the 300 Clinton emails that the department submitted were all that she had on Benghazi. Clinton is refusing to turn over her server to an independent third party, and Republicans could ultimately vote to have the full House subpoena the server. (In an interview with Bloomberg News last Thursday, Boehner said she "violated the law" with her email arrangement.)

Jamal Ware, a spokesman for the Benghazi committee, said calling Clinton to testify in a public hearing "was always going to happen" and that Gowdy requested an initial private, transcribed interview out of respect for the former secretary. "This wasn't a preference. This was a consideration for her," he told me. Gowdy also wanted to wait to speak with Clinton until the committee had all the documents it would need to adequately question her.