Immigration -- This agreement was reached bet. a handful of senators. That should not be considered a substitute for deliberation by the full Senate.

From The New York Times:

The leaderships of both parties kept their distance from the start. Mr. Reid, Democrat of Nevada, was ambivalent about the policy and political merits of the approach. Mr. McConnell, his counterpart, found himself caught among diehard Republican opponents, lawmakers open to persuasion and a president eager for a victory.

The creation of the bill, too, was highly unorthodox. Even participants in the private negotiations that led to the so-called grand bargain say their very approach created problems, producing contentious legislation embraced by the participants but met with skepticism by other lawmakers, the public and groups like organized labor and conservative research organizations.

“This agreement was reached between a handful of senators,” said Senator Jeff Bingaman of New Mexico, one of the Democrats who balked and voted against limiting debate. “That should not be considered a substitute for deliberation by the full Senate.”