Jeb Bush and Mike Huckabee have already announced they will not take part.
“This thing has been studied to death," Julian Castro said.
The GOP presidential candidate blamed the NSA's phone data collection program.
“We have to stop letting them bully us,” Carson says.
Carson took more than a quarter of the vote at the Southern Republican Leadership Conference.
The GOP 2016 hopeful says "America is not leading" on the world stage.
Christie says the Senate failed its most important task: "protecting its citizens from harm."
Julian Hattem 05/22/15 09:38 PM EDT
The Senate is set to vote on the bills at 1 a.m.