A trio of Republican senators is pushing for a special committee to investigate the 2012 attack on the U.S. consulate in Benghazi that left four Americans dead.

“We are once again calling for the appointment of a Joint Select Committee to investigate the terrorist attacks on our compounds in Benghazi,” said Sens. Lindsey Graham (R-SC), John McCain (R-AZ) and Kelly Ayotte (R-NH) in a statement Monday. “It is imperative that we learn everything that happened before, during and after the attacks. A Joint Select Committee should be established.”

The push comes as House Democrats are demanding that House Oversight Committee Chair Darrell Issa (R-CA) give up his year-and-a-half long probe into purported Obama administration mischief over the attack. Democrats accuse Issa of pursuing a witch hunt aimed at tarnishing the president and former Secretary of State Hillary Clinton ahead of a possible 2016 presidential run. To date, there isn’t evidence to implicate Clinton or senior White House officials in wrongdoing.