The dream is over. By a vote of 54-43, the Senate tabled (killed, basically) Sen. John Cornyn's amendment to plus up the border security requirements of immigration reform. Ashley Parker had a nice backgrounder on the amendment and its politics; Cornyn insisted that he wasn't trying to scuttle the entire immigration bill (he wasn't, for example, tweaking citizenship reforms), but Democrats saw that as the aftershock.
What happened? An impromptu coalition of Republicans who hadn't previously been out in front on this issue—Bob Corker, John Hoeven, Mark Kirk—announced the drafting of a different security-plus amendment. What does it contain? We don't really know, and Hoeven said every day this week that the text would come out "tomorrow." But it's likely to contain less poison than the Cornyn amendment, and be sellable as a "security first!" patch that will assuage those pesky conservative-base concerns about the border. So the holdouts will vote for that. Marco Rubio, who's starting to skid and stagger as conservatives attack his role in this bill, cast a free vote for Cornyn (i.e., he voted against tabling the amendment), which will allow him to appear on Fox News again and say he wanted greater security, but alas.