Sen. Marco Rubio, the leading Republican behind the bipartisan Gang of Eight immigration reform bill, has often said the legislation will require stronger border security measures if it is to become law. On Thursday, lawmakers got a glimpse of what that might mean.

As the Senate Judiciary Committee held its first meeting to consider a total of 300 proposed amendments to the bill, Gang members appeared willing to accept limited measures to toughen border security provisions. But the two Republican Gang members on the committee joined with majority Democrats to reject proposals that would strengthen security in a serious and far-reaching way. They also signaled a flat refusal to change the bill's plan to first legalize millions of currently illegal immigrants and only later enact new security.

One Republican amendment required 700 miles of double fencing along the U.S.-Mexico border be "substantially completed" before legalization could begin. The amendment mirrored the requirements of the 2006 Secure Fence Act, passed by the Senate on an 80-16 vote. (Among those voting yes back then were Sens. Barack Obama and Joe Biden.) The fence law was weakened in 2007, and the Gang proposal did not actually require that any new fencing be built. So Republicans proposed the 700 mile requirement. On Thursday, GOP Gang members Sens. Lindsey Graham and Jeff Flake joined all 10 Democrats on the committee to defeat the amendment.

Another Republican amendment would require Congress to certify when the border is actually secure, rather than leaving that determination to the Secretary of Homeland Security. (Secretary Janet Napolitano has said she believes the border is already secure.) Graham and Flake joined Democrats who unaminously voted to defeat the amendment.

Yet another Republican amendment strengthened the concept of "operational control" of the border as a measure of security. Graham and Flake joined Democrats to defeat that amendment.

In perhaps the key vote of the day, Sen. Charles Grassley, ranking Republican on the committee, proposed to require that new border security measures actually be finished and in place for six months before millions of illegal immigrants would be allowed to apply for legalization. "No one can dispute that this bill is legalization first, enforcement later," Grassley said. "The American people are compassionate. Many can come to terms with a legalization program. But many would say that a legalization program should be tied to border security or enforcement."

Grassley cited polls showing strong public support for enforcement first, adding that his amendment "ought not to be controversial." In fact, it was quite controversial, as Democrats quickly made clear they would not stand by for any delay in legalization. Insisting on tougher security first, Sen. Dianne Feinstein said, could "delay the triggering of the application process." In the end, Graham and Flake joined unanimous Democrats to defeat the amendment.

The committee did approve some tougher measures. For example, it unanimously passed a proposal to apply security requirements to the entire border, and not just to "high risk" sectors as the bill originally provided. The Gang had taken a lot of heat for limiting new enforcement just to "high risk" areas. In practice, "high risk" would have meant just three of the nine sectors of the border. So Democrats, joined by Graham and Flake, decided to go along with broadening the standard.

Despite that rare agreement, by the end of the day, the division in the committee was clear. All 10 Democrats, along with Graham and Flake, came together against the six other Republicans to defeat the most stringent border security suggestions.

There are many more amendments yet to consider. But the Gang got through most of the amendments dealing with border security with relatively few changes to its bill. Committee chairman Sen. Patrick Leahy, a longtime supporter of reform, seemed delighted at the work that had been done, noting proudly that most of the votes had been bipartisan -- thanks to Graham and Flake.

For critics of the bill, the failure to change key security measures brought memories of failures past, when legalization had been granted without requiring security first. Grassley, for example, was in the Senate in 1986 when it passed an amnesty measure that is seen today as a disaster, leading to a massive wave of illegal immigration. "I was one of those that made that mistake," Grassley said. "I don't want to make that mistake again."

Byron York, The Washington Examiner's chief political correspondent, can be contacted at His column appears on Tuesday and Friday, and his stories and blogposts appear on