Politico headlines their piece on Rep. Darrell Issa’s probe into the sacking of the consulate in Benghazi as his “crusade,” a term which Issa might not entirely dislike.  Refusing to take stonewalling as a final answer and armed with more information from key whistleblowers, Issa plans to hold a new round of hearings after four months of lower-key efforts to get answers from the State Department and the CIA about the circumstances that led to the deaths of four Americans:

Darrell Issa will resume hammering the White House on Benghazi on Thursday after four months of relative silence on the subject, as his committee interrogates two of the chief independent investigators of the attacks on the U.S. diplomatic outposts in Libya.

Issa’s House Oversight and Government Reform Committee will basically investigate the independent investigation by the Accountability Review Board. The ARB released a December report detailing the Obama administration’s response to the attacks, calling for tighter security at many embassies but stopping short of laying blame on senior officials in the State Department. …

Republicans have accused Mullen and Pickering of protecting [former Secretary of State Hillary] Clinton in their report by not citing her for any breaches of leadership. By pushing back at their report — both at the methods and the content — Republicans hope to erode one of the biggest defenses of Clinton.

“The takeaway is going to be that diplomatic security continues to be a political and policy decision,” Issa told POLITICO. “The State Department, that not providing sufficient security for the ambassador and the consulate personnel was a policy decision more than a professional security decision.”

Democrats tell Politico that the testimony of Pickering and Mullen will vindicate the ARB, but that seems unlikely.  Pickering himself admitted that he only interviewed lower-level State officials because he had decided beforehand where the blame should be fixed, telling Bob Schieffer in May, “We knew where the responsibility rested.”  The ARB ignored Undersecretary Patrick Kennedy, who made decisions on consulate security, but who also was a key aide to the Clintons during Bill Clinton’s presidency and during all of Hillary Clinton’s tenure at State.

Will Issa get Hillary Clinton back to testify?  The Daily Mail reports that a subpoena might be in the offing:

Republicans are mulling whether to demand former Secretary of State Hillary Clinton’s return to Capitol Hill to face more tough questions about her agency’s failure to protect diplomats and security staff in Benghazi, Libya a year ago.

An aide to a high-ranking GOP member of the House Oversight and Government Affairs committee told MailOnline that the committee’s chairman, California Rep. Darrell Issa, ‘is dead serious’ about raking the likely 2016 presidential candidate over the coals in the future.

‘Look, it’s not like we’re getting great answers from the deputies and under secretaries,’ the staffer said on Wednesday. ‘So eventually you have to climb the ladder and swear Hillary in again.’

‘I’m not saying “The fish stinks from the head,” or anything like that,’ the aide cautioned. ‘Just that the committee leaders on our side want answers and they’re not going to let up.’

Issa told the Fox News Channel on Wednesday morning that his committee won’t hesitate to bring back any of the senior-level witnesses who have already testified about the September 11, 2012 terror attack on American diplomatic facilities in the eastern Libya port city.

And that includes Hillary Clinton.

‘We can certainly have Mrs. Clinton back,’  Issa told Fox. ‘We want to be respectful of her time, so getting to the facts – including people below her – first is critical.’

Issa sounds less inclined to issue a subpoena than to force Hillary back to the panel on her own volition.  Undermining the ARB report will be a first step, and I’d expect that Issa has confidence in his ability to do that.  Otherwise, he’d skip calling Pickering and Mullen and just focus on the CIA survivors, who will eventually get subpoenaed to testify.  With the previous testimony from State Department whistleblowers in hand, Issa will next aim at Kennedy — and will be bolstered in that effort by an independent review that named Kennedy as a responsible party, unlike the ARB, a discrepancy that Issa will no doubt highlight.

If they build the case all the way to Kennedy, that will put a lot of public pressure on Hillary to make an appearance at the Oversight hearings, which takes the onus off of Republicans to issue a subpoena.  At that point, Issa will issue a public invitation to Hillary to address the issues that have arisen from a multitude of sources about the incompetence and deceit at State during her tenure.  If she refuses to appear, that’s not going to look good, regardless of whether she wants to run for office later or not.  It won’t prevent Oversight from making a damning case about her leadership at State, either.

What about the Senate?  Will they conduct their own investigation into Benghazi, where Democrats can control the probe?  Ted Cruz offered an amendment with Pat Toomey yesterday to launch a joint effort with the House, but Barbara Boxer immediately objected (via Twitchy):