“This thing has been studied to death," Julian Castro said.
The GOP presidential candidate blamed the NSA's phone data collection program.
Rubio said Clinton's ideas "play by the rules of yesterday's economy."
Christie said he was the "only person in this national conversation" to use the Patriot Act.
The emails won't be made public after the ruling from the government's chief records officer.
Her profile lists her as a "2016 presidential candidate."
“I think he could have used the veto power,” Jeb Bush said.
Rep. John Ratcliffe praised Cruz's "unwavering conservative values."
Jindal said he is "sympathetic" to Rand Paul's calls to limit the NSA.