When President George W. Bush signed the ban on “partial-birth abortion” into law in 2003, it marked a decisive victory for anti-choice advocates. It set the stage for increasingly restrictive attacks on abortion, including on the most common form of second-trimester abortion. And Judge Brett Kavanaugh, President Trump’s pick to replace Justice Anthony Kennedy whose confirmation hearings begin this week, may have had a hand in delivering conservatives that victory.

The move marked a jarring disrespect for abortion rights jurisprudence. A Republican-led Congress had passed similar measures in both 1995 and 1997, only to see them vetoed by Democratic President Bill Clinton. In 2000, anti-choice conservatives watched as the U.S. Supreme Court struck down an identical Nebraska law banning “partial-birth” abortions in Stenberg v. Carhart. But then Bush won the 2000 election and anti-abortion forces had an ally in the White House again. They intended to make the most of it. They pushed ahead with the federal “partial-birth” abortion ban even though the Supreme Court had struck down a similar ban in Stenberg. And in 2007, the Supreme Court ruled it constitutional in a decision authored by Justice Kennedy.

Kavanaugh served as White House staff secretary during the administration’s support, and later legal defense, of the federal ban. His role in the battle may have been minor. He may have simply been, as Senate Republicans have insisted, nothing more than a “paper pusher” while serving as White House staff secretary during those years.

That’s a claim, by the way, that previous staff secretaries dispute. In an interview with HuffPost , Lisa Brown, White House staff secretary for President Barack Obama explained the job like this. “There’s no question their role is to be an honest broker, but you are also driving this process,” Brown, told HuffPost. “So you’re not just a paper pusher … you’re playing a much more overt role.”

But in an unprecedented lack of transparency, Republicans refuse to release some documents related to Kavanaugh’s tenure at the White House. That refusal means the extent of Kavanaugh’s work for the Bush White House on the ban remains a mystery—even as the Senate Judiciary Committee is set to begin hearings on his nomination.

“At a minimum, something that he authored, commented on or edited could be relevant to understanding his views,” Brown said. “And if the question is what he knew about a specific topic, then any materials on that subject that he received would also be relevant.”

To be clear, we basically know where Kavanaugh stands on abortion rights and he is not generally for them. He wrote an opinion in Garza v. Hargan that would have blocked access to an abortion for an undocumented minor, and he’s praised dissents in Roe v. Wade that deny the fundamental autonomy of pregnant people. There’s also the fact that President Trump promised to nominate justices to the Supreme Court that would overturn Roe v. Wade. And if we’ve learned anything in Trump’s first two years it is to take the worst of his promises at face value. 

But what documents related to Kavanaugh’s time at the White House could tell is us is how involved Kavanaugh was in crafting a strategic response to a Supreme Court decision anti-choice advocates didn’t like in Stenberg v. Carhart that would ultimately result in the Supreme Court affirming the federal “partial-birth” abortion ban and hand anti-choice forces one of their most decisive victories to date. How can Kavanaugh claim to “respect precedent” like Roe v. Wade if he spent years working strategically to undermine it? 

This is exactly the kind of question Kavanaugh should face from members of the Senate Judiciary Committee during his confirmation hearing. The question is, will he?

It’s not just Kavanaugh’s possible work on the “partial-birth abortion” ban that remains a mystery. So is the extent of his work on Bush-era torture and detainment policy. As is a clear picture of his views on executive power and whether or not a sitting president can be indicted for criminal conspiracy, for example. And while we can guess what those views are just by the fact that Kavanaugh cleared the vetting process to be a Trump nominee, the entire point of the Senate’s constitutional advice and consent power is to make sure there are no guesses when it comes to lifetime appointments. To be sure, some senators like Mazie Hirono (D-HI) or Patrick Leahy (D-VT) will likely press Kavanaugh on these and other points. But they’ll be doing so without the benefit of Kavanaugh’s full record, which is exactly the purpose of Republicans’ failure to release the documents.

So far, Senate Democrats have raised objections to the pace of the Kavanaugh nomination and confirmation proceedings and to the Republican failure to make his full record ready for review prior to the start of his hearings. But aside from some furious finger-waggling and podium-pounding, they have done little else. They have not, for example, denied Republicans a quorum, which in this case would force each Senate Republican to stay in Washington, D.C., and be available to cast votes instead of campaigning ahead of themidterms. Nor have they even indicated they’d consider doing so. Such a procedural move wouldn’t block Kavanaugh’s nomination permanently—Democrats just don’t have the votes to do so without peeling away a few Republicans—but it would force Republicans to work for their victories instead of simply receiving them on a silver platter. Democrats are the opposition party, but you’d never know it by their actions so far.

Perhaps the hearings will prove that record wrong.