As we await the president’s speech on immigration reform (due to be delivered at 2:55 EST in Las Vegas), the much-ballyhooed Senate Gang of Eight agreement on the subject continues to spring leaks. WaPo’s Greg Sargent puts his finger on the main problem:

One of the central questions about the Senate’s new immigration plan remains: Does the new Southwestern border commission it creates have to declare the border secure before the path to citizenship is triggered?

The answer is central to the prospects for reform. If the answer is Yes, the commission could give veto power over the fate of 11 million undocumented immigrants to the likes of Jan Brewer. Yet the bipartisan Gang of 8 Senators differ on this.

On CBS this morning, John McCain said the “final decision” about whether the border is secure will be made by the Department of Homeland Security, which suggests a diminished role for this commission, while remaining inconclusive on precisely how this process will work. But in an interview with Ed Morrissey late yesterday, Marco Rubio suggested he won’t support a path to citizenship unless the commission does sign off on border security, a position he reiterated in another interview. There’s no clear agreement even among Republicans about the role of this commission.

Meanwhile, Dem Senate aides tell me that the commission’s role is designed to be purely advisory and nonbinding. At the same time, Chuck Schumer’s office declined to respond to my request for clarification on this point.

Can we get a straight answer on this, please?

Well, often in politics key questions are left unanswered or left to the imagination of listeners when agreement is difficult or impossible. “Enforcement must come first” has been the principal conservative objection to comprehensive immigration for decades. Supporters of reform are forever offering tougher enforcement in exchange for a path to citizenship, but such offers are rarely considered sufficient unless they involve identifying, exposing and punishing every undocumented person before they become eligible for legalization. To the extent that the Gang of Eight’s proposal actually identifies an entity in charge of determining that enforcement has become sufficient, it’s a big step forward. But if it transpires that even the authors can’t answer basic questions about it, any step forward may soon be reversed.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.