White House move sets off lawmaker questions over 'Fast and Furious'

Republican leaders in both chambers are raising sharper questions about the White House's involvement in the controversial "Fast and Furious" program after President Obama invoked executive privilege to withhold documents from Republican investigators.

Both the White House and U.S. Attorney General Eric HolderEric H. HolderLawyer claims death threats after anti-Black Lives Matter lawsuit Adviser: Obama can’t ‘erase decades’ of racism Airbnb enlists civil rights leaders in discrimination fight MORE have claimed repeatedly that high-level officials – both in the Department of Justice and in the White House – were unaware of the nature of the botched program, which put firearms into the hands of known gun-runners in an effort to trace them to drug-smugglers along the Mexican border.

But with the White House moving unilaterally Wednesday to assert executive privilege over documents sought by the House Oversight and Government Reform Committee, Republicans have grown more suspicious that those officials knew more than they've claimed.

Sen. Chuck GrassleyChuck GrassleyMcConnell blames dysfunction on Dems Four states sue to stop internet transition Senate passes bill to preserve sexual assault kits MORE (Iowa), the senior Republican on the Senate Judiciary Committee, said the administration's maneuver "raises monumental questions" about who knew what – and when. 

"How can the president assert executive privilege if there was no White House involvement? How can the president exert executive privilege over documents he's supposedly never seen?" Grassley, who met with Holder Tuesday night, said Wednesday in a statement. "Is something very big being hidden to go to this extreme? ... The questions from Congress go to determining what happened in a disastrous government program for accountability and so that it's never repeated again.”

The office of House Speaker John BoehnerJohn Boehner3 ways the next president can succeed on immigration reform Republican Study Committee elders back Harris for chairman Dems to GOP: Help us fix ObamaCare MORE (R-Ohio) was quick to raise similar concerns.

"Until now, everyone believed that the decisions regarding ‘Fast and Furious’ were confined to the Department of Justice," BoehnerJohn Boehner3 ways the next president can succeed on immigration reform Republican Study Committee elders back Harris for chairman Dems to GOP: Help us fix ObamaCare MORE spokesman Michael Steel said in an email. "The White House decision to invoke executive privilege implies that White House officials were either involved in the ‘Fast and Furious’ operation or the cover-up that followed. 

"The administration has always insisted that wasn't the case," Steel added. "Were they lying, or are they now bending the law to hide the truth?"

Launched by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), the Fast and Furious program was designed to battle drug dealers by following guns from the border states into Mexico. But the agency lost track of hundreds of those guns, and several were linked to the murder of an Arizona border patrol agent in late 2010.

The mismanaged program captured the attention of House Oversight Committee Chairman Darrell Issa (R-Calif.), who launched an investigation and has spent months hounding Holder to release more documents detailing the operation.

Saying Holder has refused to comply, Issa called a Wednesday vote to hold the attorney general in contempt of Congress.

The saga has been largely partisan, with Democrats on Wednesday accusing Issa and the committee Republicans of staging a politically motivated witch hunt.

“This is a mistake, a major mistake,” Rep. Edolphus Towns (D-N.Y.) said during Wednesday's hearing. “It’s the most ridiculous thing that I think I’ve seen in my years of being on this committee.”