"Grand bargain" supporter and presidential candidate John McCain (R-AZ) says that lack of trust was one of the reasons why this bargain failed: "We said we'd secure the borders. Americans didn't believe us." He says he continues to back "comprehensive immigration reform."
Forbes has more:

"We believe the comprehensive approach to immigration failed because the American people do not have trust and confidence in the government and Washington to do what we say.["]
[...]
McCain said "I still believe we need a temporary worker program - we need to address the 12 million people who are here illegally."

"But the point is, we have got to secure the borders," he said.