Sen. Rand Paul and Judge Andrew Napolitano responded this morning to proponents of NSA bulk surveillance, arguing that a more focused surveillance program could have stopped the Boston Marathon bombing. 

In his interview earlier on "America's Newsroom," Paul called out his critics for trying to use "fear" to convince Americans that the current version of the Patriot Act should be renewed. 

He said some are claiming that the mass collection of Americans' phone records is needed to stop terror attacks, like the Boston bombing. 

Napolitano agreed with Paul that the argument does not hold up.

The judge said Russian authorities warned the FBI about the older brother, Tamerlan Tsarnaev, and that that information alone would have been enough to get a warrant from a judge for NSA surveillance. 

"By forcing the government to comply with the Constitution, [present] probable cause, some evidence of wrongdoing about the person's calls you want to intercept, it gets rid of the suspicion-less, excess information [being gathered]," said Napolitano.

Martha MacCallum pointed out that the other side will say, 'God forbid there is an attack, and afterward we find out that there was a phone call that we could not intercept.'

The judge said when people are afraid, they "have a natural inclination to want to go into government's comforting arms."

"The government's job is to keep us free and safe. If it keeps us safe but un-free, it's not doing its job. Not everyone agrees with that," he said.

Hear the judge's full thoughts above.