"Schiff said Prism was more popular in congress for two reasons. First, Prism "is focused outside the United States and not on US citizens". Second, Schiff said its effectiveness is "much more substantial" than the phone records collection.

Intelligence officials have struggled to show how collecting bulk phone metadata was critical to foiling even one terrorist plot."

https://www.theguardian.com/world/2013/aug/02/congress-nsa-legislation-surveillance