I hung out in the Senate yesterday as 67 members of the World's Greatest Deliberative Body agreed to debate an omnibus immigration bill amended to include border controls, like 20,000 more agents, proposed by Republicans. The going theory has been "a supermajority in the Senate will move minds in the House." I've always been skeptical and found new reasons for that skepticism as ... well, as members of the House talked about it.
John Dickerson trained his sights on the Senate, too, and came up with this theory of how all the concessions by Democrats—which their House counterparts see as moving the bill right—will be good for reformers.
A big Senate victory would also give supporters a way to minimize future debate about the controversial portions of the bill. The House is expected to pass a series of smaller immigration bills but no path to citizenship, which is the heart of the Senate effort. If a House Republican takes issue with a particular element of Senate reform, a supporter will claim the issue was already debated and resolved in the Senate.
It's a theory, anyway.
Correction, June 25, 2013: This post originally misspelled John Dickerson's last name.