The Senate immigration bill lacks the 60 votes it needs to clear the chamber, a key lawmaker confirmed Tuesday.

Sen. Bob Menendez said during a brief interview that he was "confident" the legislation would ultimate attract the 60 votes, and perhaps more by the time the final votes are tallied. But consistent with my report on the status of the bill published Monday evening, the New Jersey Democrat and "Gang of Eight" member indicated that the legislation's border security measures would need to be strengthened to attract the Republican support it needs to pass.

"I think we'll get the 60 votes; I think we'll get beyond 60 votes. How much beyond is an open question," Menendez said. "But I'm feeling more confident as we talk to members on both sides of the aisle, as they get to understand what's in the bill."

But to get to 60, never mind beyond, the majority Democrats are going to have to support Republican amendments to beef up the border security components of a comprehensive reform package that makes many in the GOP nervous politically because it would immediate legalize millions of illegal immigrants already living in the U.S. and put them on a 10- to 15-year path to citizenship.

Republicans, including crucial "gang of eight" member Sen. Marco Rubio, R-Fla., remain concerned with other provisions that give broad discretion to the Department of Homeland Security and the executive branch to determine whether benchmarks for border security are being met. Republicans want Congress to provide the administration with more specific language that would make it clear whether these border security triggers are being satisfied as the bill intended.


Because if they aren't, the path to citizenship for newly legalized immigrants provided for in the legislation would be halted. This is how Republicans who support the bill believe they can ensure that Democrats don't achieve legalization without having to deliver on border security, as happened when former President Ronald Reagan supported citizenship for illegal immigrants in 1986.

Here's what Menendez had to say when I asked him if Democrats are likely to support such amendments:

"We have deferred to our colleagues on the other side of the aisle to a great degree on what the border security plan looks like. And so, if specificity is what they're seeking, that's fine as long as the specificity can be, No. 1, achieved; and, No. 2, isn't simply used as an impediment to stop the pathway to legalization from taking place."

The Senate immigration bill is scheduled to hit the floor on Monday.