For the first time since Edward Snowden revealed some of the National Security Agency’s (NSA’s) surveillance programs last June, a congressional committee has voted to send legislation intended to curb the government’s spying power on for a full vote. On Wednesday, the House Judiciary Committee passed a version of the USA Freedom Act, considered by civil liberties advocates to be among the strongest of several competing reform bills.

But what lawmakers voted unanimously to approve is a trimmed down version that is narrower in significant ways. The revision is the result of an agreement crafted by members of the Judiciary Committee— including Republican chairman Bob Goodlatte, who voted previously against an attempt to limit the NSA’s reach—in a bid to win wider support. In its compromised form the bill is more specifically focused on the phone records program and the statute that authorizes it, Section 215 of the Patriot Act.

Under the amended version of the bill, the government itself would no longer be allowed to hold a database of people’s calling records, and would have to seek a judge’s order before collecting data held by the telecom companies—a change that President Obama has said he would support. The bill would also increase transparency by allowing phone companies to inform the public about the requests for data they receive.

“I think we can call it a milestone. It is the first bill that’s really got momentum behind it and that would truly rein in the bulk collection programs,” said Gabe Rottman, legislative council for the American Civil Liberties Union. Still, he acknowledged that the amended version “is a compromise bill, and it’s not as strong as the original sense of the proposal.”

Cut out of the amended version is a ban on unauthorized “back door” searches, the practice of mining a database of foreigners’ communications for the emails and phone calls of American citizens. Such searches are made under a different authority, Section 702 of the Foreign Intelligence Surveillance Act (FISA), which lawmakers left untouched during Wednesday’s markup. The amendment also softened reforms to the secret court that authorizes the NSA’s surveillance activities, and preserved the requirement that the government need only prove “reasonable articulable suspicion” that records sought are relevant to an open investigation—the NSA’s preferred relevancy standard.

“Right now, [the USA Freedom Act] is good on one small piece of the surveillance pie,” said Mark Jaycox, a legislative analyst at the Electronic Frontier Foundation. “It is a good step towards fixing Section 215, but it’s lacking in what the USA Freedom Act originally envisioned, which was an overarching bill that touched on many of the different spying authorities and activities we’ve learned about.”

California representative Zoe Lofgren proposed a number of amendments intended to restore the bill to its wider scope. “The biggest disappointment I have about the [amended version] is that it took meaningful reform… and watered it down significantly,” Lofgren said as she argued for reinstating the ban on back door searches. But Lofgren’s revisions were shot down even by James Sensenbrenner, the Republican co-author of the original USA Freedom Act, who summed up the prevailing attitude when he cautioned his colleagues “not to make the perfect the enemy of the good.”

“We finally have a bill that can actually pass, and this amendment would probably upset that ability to pass a bill,” said New York Democrat Jerrold Nadler, who objected to a Lofgren proposal to raise the relevancy standard from reasonable articulable suspicion to a tougher requirement that the government demonstrate probable cause. Nadler called the act “the first, best and perhaps only chance in a decade” to reform the NSA.

The revisions to the bill were significant enough to earn tentative approval from one of the NSA’s most ardent allies, Intelligence Committee chairman Mike Rogers. After the Judiciary Committee made a surprise announcement early in the week that it would move on the USA Freedom Act, Rogers immediately announced the Intelligence Committee would, on Thursday, mark up his own bill, the FISA Transparency and Modernization Act, which is much softer than the original USA Freedom Act.

But the distinctions between the two have grown sufficiently murky to prompt Rogers to indicate that he might end up supporting the USA Freedom Act after all. “They’ve come a lot closer [and] now we’re just trying to work out the wording,” Rogers told Foreign Policy on Tuesday. Important differences do remain, however; under the Rogers legislation, for example, the government would not need a judge’s permission to probe phone and email data.

In general, civil liberties advocates are pleased that Congress is finally moving on surveillance reform, even if addressing Section 215 only gets at one of the programs revealed so far by the Snowden documents. Besides Section 702, there are untouched issues related to an executive order expanding presidential authority (Executive Order 12333), the use of which for legal grounding for spying activities in not yet well understood. But because the phone metadata program is easiest to understand and has attracted the most attention, it’s not surprising that it is Congress’s first target. The bill is likely to have strong support on the floor, particularly as it is now closely aligned with changes explicitly supported by Obama and has been made more palatable to people like Rogers.

But there’s valid concern that the phone records program will turn out to be a sacrificial lamb for the administration, something given up in the hopes that Congress will wash its hands of the rest. The dragnet is not disappearing under the USA Freedom Act; metadata will still be available to the government, if not quite so freely; and a single court order will allow officials to explore phone records two “hops” away from the initial target—potentially millions of records. It’s unclear whether the bill explicitly bars intelligence agencies from collecting the contents of communications under Section 215, a provision that originally distinguished the USA Freedom Act from Rogers’s bill. Though the ban was absent in the version that passed the committee, Lofgren speculated that the omission was due to a clerical error. What’s for sure is that Congress’s ability to truly reform—and oversee— the intelligence community remains unclear.

“Certainly there’s a concern that they can say, ‘we fixed it and we’re done.’ But I don’t think that any of the groups that are concerned about this or, frankly, the American public will let that happen,” Rottman said.

Several of the NSA’s critics in Congress said that they too will continue to press for stronger measures. “I remain concerned that the legislation approved today does not include some of the important reforms related to national security letters, a strong special advocate at the FISA Court, and greater transparency,” Vermont senator and Judiciary chair Patrick Leahy said in a statement. “I will continue to push for those reforms when the Senate Judiciary Committee considers the USA Freedom Act this summer.”

Oregon Senator Ron Wyden said he “will continue to fight for additional steps to protect both American security and American liberty, like closing the back door searches loophole and installing a constitutional advocate at the Foreign Intelligence Surveillance Court.”