Rep. Trey Gowdy (R-SC) has worn his promises that the House Select Committee on Benghazi’s investigation is nonpartisan and “fact-centric” like armor ever since he took up the mantle of leadership on the panel.

But chinks in that armor are showing just days before Gowdy is set to grill Democratic presidential frontrunner Hillary Clinton in a high-profile, public hearing. Ramped-up pressure from Democratic members of the panel in addition to GOPers’ assertions that the investigation targeted Clinton have made Gowdy appear to be the lone voice still crying out for the “truth” behind the Benghazi attacks. The House GOP hasn’t exactly sent in reinforcements for Gowdy, either, as its members continue to preoccupy themselves with finding a replacement for outgoing Speaker John Boehner (R-OH) who can satisfy both the establishment and insurgent wings of the bitterly divided chamber.

“I would say in some ways these have been among the worst weeks of my life,” Gowdy told Politico in an interview published Sunday. “Attacks on your character, attacks on your motives, are 1,000-times worse than anything you can do to anybody physically — at least it is for me.”

That quote reveals just how vulnerable of a figure Gowdy has become, and at a most inopportune moment for him. Instead of telegraphing what Clinton can expect from him and the rest of the panel when she arrives Thursday on Capitol Hill, the chairman has been publicly chiding the GOP caucus to “shut up” about the Benghazi investigation lest they further undermine the high-stakes hearing.

Things weren’t always this difficult for Gowdy. It was apparent that the Benghazi attacks were the preferred distraction meme of the Republican Congress and conservative pundits alike long before House Majority Leader Kevin McCarthy’s (R-CA) now-infamous “gaffe,” but the hard-nosed former federal prosecutor considered himself above the partisan fray.

“Twenty months after the Benghazi attacks, there remain unresolved questions about why the security was inadequate, our response during the siege itself, and our government’s interaction with the public after the attack,” Gowdy said in a statement when the panel was formed in May 2014. “All of those lines of inquiry are legitimate and should be apolitical. Facts are neither red nor blue.”

The select committee’s work was rather slow up until March of this year, when its activity kicked into overdrive after its reported discovery that Clinton exclusively used a private email account during her tenure at the agency. When McCarthy touted the panel’s negative effect on Hillary Clinton’s poll numbers last month during an interview with Fox News’ Sean Hannity as an example of what kind of leader he’d be as House speaker, the attention the panel paid to Clinton’s emails suddenly seemed a lot more nefarious.

McCarthy’s comment gave Democrats and Clinton’s camp a golden opportunity to cast the select committee as a partisan cudgel designed to damage the former secretary of state’s presidential campaign. It cost McCarthy his shot at succeeding Boehner and momentarily allowed Gowdy’s profile to rise even as the congressional GOP floundered without a speaker-apparent. Some of the same arch-conservatives who cheered Boehner’s resignation began to float Gowdy’s name for majority leader. The Benghazi chairman, via a spokesperson, shot down speculation that he was seeking a leadership position and vowed to remain focused on his probe into the 2012 terror attacks.

There were other disturbances in the Benghazi force as well. A former Republican staffer for the select committee, Air Force reserve Major Bradley Podliska, accused the panel earlier this month of carrying out a “partisan investigation” into Clinton. Podliska also claimed that he was fired in part for resisting pressure from his superiors to target the former secretary of state after the reports about her use of a private email server emerged.

Gowdy dismissed the allegations he said came from an ex-staffer he never even met. He later described Podliska as a disgruntled ex-employee in the interview with Politico. But a third suggestion that the panel “was designed” to go after Clinton, this time from Rep. Richard Hanna (R-NY), finally prompted Gowdy to go nuclear.

“I have told Republican colleagues and friends ‘shut up talking about things that you don’t know anything about,’” the chairman said Sunday on CBS’ Face The Nation. “Unless you’re on the committee, you have no idea what we have done, why we have done it and what new facts we have found.”

It’s possible that Gowdy’s struggle to keep House GOPers on the same page about the Benghazi panel in terms of messaging could be a symptom of the chamber’s leadership vacuum. But the chairman’s own recent, unforced errors can’t be attributed to the leadership chaos in the Republican caucus.

Gowdy appeared to accidentally release the name of a CIA source after falsely accusing Clinton of mishandling classified information by forwarding an email containing the source’s name to an aide. The chairman released the full text of the email Sunday leaving the source’s name unredacted in the subject line, despite writing to the panel’s ranking Democrat that “we remain concerned with the naming of sources and methods and will continue to protect that information.” The State Department later copped to failing to redact the name for privacy—not sensitivity—reasons before releasing the email to the Benghazi panel.

The chairman on Friday also returned donations indirectly linked to a political action committee that aired a nasty, anti-Hillary Clinton ad related to the Benghazi attacks after an inquiry from The Washington Post.

Republicans remained largely silent this week even as Democrats dragged Gowdy’s name through the mud. In a Monday appearance on MSNBC, select committee member Rep. Linda Sanchez (D-CA) accused the chairman of trying to “smear” Clinton by suggesting she was personally responsible for security failures at the Benghazi compound. Rep. Elijah Cummings (D-MD), the ranking Democrat on the panel, responded to the report about Gowdy’s refunded donations with a statement that said the chairman’s ties to the Stop Hillary PAC treasurer “directly contradict the promise we made to the families of the four brave Americans.”

Gowdy enjoyed widespread support when Boehner appointed him as chairman of the select committee. But it appears that the Benghazi committee has become so radioactive and the search for a new speaker so wearying that Gowdy’s fellow Republicans won’t stick their necks out for him when he needs their backing the most.