The Trump travel ban’s waiver process is supposed to allow deserving nationals from the affected—mostly Muslim-majority—countries the opportunity to get visas. This waiver process was added to the second and third travel bans after the first was struck down by multiple courts. In oral arguments in the Supreme Court travel ban case Trump v. Hawaii, a pair of justices wondered whether the waiver process was just “window dressing”—an effort to present the president’s long-promised “Muslim ban” as a standard immigration measure.

Since the enactment of the third travel ban, the State Department has been reluctant to divulge specifics about the waiver process. Muslim Advocates and the Center for Constitutional Rights issued a FOIA request in January for internal government documents pertaining to the waiver process but have yet to receive any documents in reply. Immigration attorney Julie Goldberg has attempted to get more information about that process several times during legal proceedings, to no avail. And last week, I asked the State Department a series of detailed questions about the ban’s waiver process and was offered no comment.

The only person who has had success in getting information from the State Department is Sen. Chris Van Hollen, who was sent a letter in February that showed that just 0.02 percent of applicants received waivers between Dec. 8, 2017 and Jan. 8, 2018. The State Department has since offered updates on the number of waivers it’s issued—that number was 809 as of June 15. But as Neal Katyal, who argued for Hawaii in the travel ban case, told the Supreme Court in April, the total number of visa waivers the State Department has issued is meaningless if we don’t know the total number of applicants. Thus far, the agency hasn’t provided that information, despite a direct request in April from Van Hollen and other Democratic senators.

Now, Van Hollen may have found a way to force the State Department to publicize those numbers. The Democratic senator from Maryland has successfully pushed passage of an amendment to the 2019 State, Foreign Operations, and Related Programs Appropriations Act that requires the secretary of state and relevant federal agencies to release the total number of applicants who have been denied waivers under the president’s travel ban. That act, which easily made it through committee on a bipartisan basis, will now head to the Senate floor for a final vote before eventually going to a House-Senate conference committee. If the language on waivers stays in this mandatory appropriations measure, it could force the State Department to be more transparent about its travel ban waiver process.

In an interview on Thursday, Van Hollen said he believes the State Department has been hiding the relevant data because it will embarrass the administration and reveal the travel ban to be what it is—another Muslim ban.

“The purpose of the amendment is to provide some long overdue transparency about the waiver process,” Van Hollen told me.

“Our impression is that they’re trying to hide this information because they know if it comes to light it will expose the program as a sham.”

Slate asked the State Department if it had a response to Van Hollen’s allegation, but did not receive a response prior to publication time.