A little over two months ago Obama's top official at the Centers for Medicare and Medicaid Services (CMS), Marilyn Tavenner, assured members of a congressional oversight committee that the ObamaCare exchanges rollout was right on schedule. 

Tavenner from August 1 testimony:

This is a large and complicated endeavor that I am proud to lead, and every decision is being made by my prior work experience.

Representative Eric Cantor (R-VA) has been a longtime friend and supporter of Tavenner. When he introduced his fellow Virginian at her Senate confirmation hearing in May he stated, "If there is anyone that I trust to try and navigate the challenges, [of Obamacare] it is Marilyn Tavenner."

Tavenner and Cantor will have to eat those words today when she goes before the House Ways and Means Committee to explain what went wrong on October 1.

How heavily involved is the former nurse and hospital executive? The White House visitor logs show she was cleared to visit the White House 425 times between December 2009 and June 2013, including several meetings with Obama himself. Globalpost reported "one Oval Office meeting with Obama in March would have occurred as some technology officials in her agency publicly fretted about the possibility that the complicated website would malfunction, telling an insurance forum they were working to avert problems."

GOP lawmakers, the same ones who overwhelmingly supported Ms. Tavenner's nomination and confirmation last spring, are hoping she will be forthcoming. Joe Antos, a healthcare analyst with the American Enterprise Institute said Tavenner is "more responsible for decisions made at CMS that probably led to this disaster."

House Republicans will question Ms. Tavenner on who made her agency responsible for the integration of the sprawling information technology system behind the government website. Officials have now turned the problem portal over to a private contractor, a decision some experts say should have been made in the first place.

So far, Tavenner has kept a low-profile. With scant attention from the media, she has managed to be an avid supporter of her predecessor Dr. Donald Berwick's plan to cut costs by rationing healthcare, without drawing any ire from the public. But that all could change today. 

For more background on Marilyn Tavenner see my other American Thinker posts:

Obama's Problematic New Nominee for Top Medicare/Medicaid Post
CMS Marilyn Tavenner's Skeletons Ignored by Senate Finance Committee