Senate Democrats blocked Sen. Ted CruzRafael (Ted) Edward CruzTed Cruz and Bill Nelson give NASA a reality check on privatizing International Space Station Ten dead after shooting at Texas high school Hillicon Valley: Lawmakers target Chinese tech giants | Dems move to save top cyber post | Trump gets a new CIA chief | Ryan delays election security briefing | Twitter CEO meets lawmakers MORE (R-Texas) from passing a resolution to form a select committee to investigate the Sept. 11, 2012, terrorist attack on the U.S. Consulate in Benghazi, Libya.

“What is truly chilling is that in the 20 months after the Benghazi attack is that we have four dead Americans and no dead terrorists,” Cruz said on the Senate floor Monday. “The clock is ticking, memories are fading [and] it is beyond time to get the resources of both chambers of Congress behind this investigation.”

Four Americans were killed in the attack, including U.S. Ambassador Chris Stevens, but none of the terrorists involved in the attack have been captured.

Last week, Speaker John Boehner (R-Ohio) announced the members of a select committee to investigate the administration’s response to the attack.

Cruz tried to get unanimous consent to pass S.Res. 225, which would have called for a Senate investigation as well, but Senate Foreign Relations Committee Chairman Bob Menendez (D-N.J.) objected.

Cruz listed 10 questions he said should be answered by the committee, including whether President Obama was sleeping on the evening of the attack and why there wasn’t more security at the U.S. Consulate, located in a volatile area.

“Did President Obama sleep the night of Sept 11, 2012? Secretary [of State Hillary] Clinton has also not answered that question,” Cruz said. “It is chilling to imagine that our own president had more pressing things to attend to than a terrorist attack on our own people.”

Menendez, who said Cruz’s motion was “purely a political witch hunt,” then asked to pass S. 1386, a bill to increase U.S. embassy security, but Cruz objected.

“Are you actually interested in saving lives or just making political points?” Menendez said. “If you want to save lives where you have control, then you will let the embassy security bill go forward.”

Republicans originally criticized the administration for saying the attack was caused by political demonstrators ahead of Obama’s reelection. The issue has been raised again recently because of released White House emails of talking points.

Democrats say Republicans are simply using the issue to gin up support ahead of the November election.

If Clinton and Cruz both decide to run for president in 2016, this issue will likely be raised again.