WASHINGTON — The National Archives and Records Administration said Thursday it won't be able to finish reviewing nearly 1 million documents regarding Supreme Court nominee Brett Kavanaugh's time in the George W. Bush White House until the end of October, a potential roadblock in GOP hopes for confirmation before the November election.

Republican leaders in the Senate appeared unfazed by the updated timetable, determined to push forward with confirmation hearings on President Donald Trump's nominee next month, even if the documents are not fully available.

The paper chase over Kavanaugh's lengthy public record is emerging as a key battleground as senators scrutinize the 53-year-old appellate judge, a conservative whose views on gay marriage, abortion and executive power could tip the court rightward for a generation.

The documents being compiled by Archives are only the initial request from Republicans. It covers Kavanaugh's time in the White House counsel's office and his nomination to be a judge. But the files won't contain the broader cache being sought by Democrats from Kavanaugh's time as Bush's staff secretary, where an additional 1 million pages passed his desk.

A spokesman for Republican Sen. Chuck Grassley of Iowa said the Judiciary Committee will still be able to undertake its review along the same timeline set previously, which puts Kavanaugh on track for confirmation in early October. The chairman "intends to hold a hearing sometime in September," Taylor Foy said.

While Republicans could hold confirmation hearings before receiving all the documents, a final vote on Kavanaugh may have to wait. With Republicans holding a slim 51-49 majority in the Senate, cooperation from almost all Republicans would be needed to push ahead.

Senate Minority Leader Chuck Schumer said the letter Thursday from the Archives to Grassley "confirmed our worst fear" — that even the documents requested by Republicans may be limited because they will be screened by Bush's lawyer under the Presidential Review Act.

The New York Democrat said because the lawyer has also represented top Trump administration officials in the Russia probe, including former strategist Steve Bannon and former chief of staff Reince Priebus, the process appeared designed to withhold "the information they need" to evaluate the nominee.

Even before Thursday's developments, Republicans blasted the Democratic demands as delay tactics.

Standing before stacks of boxes that will be filled with documents from Kavanaugh's other jobs — an initial cache of 125,000 documents is expected later this week — Grassley and other top GOP senators argued there will be ample paperwork to review, including Kavanaugh's 300 cases as an appellate judge.

Grassley called it probably the "deepest dive" ever conducted on a Supreme Court nominee. Since several Democratic senators have already announced their votes against Kavanaugh, he questioned "the sincerity of demands" for more.

"What more do they need to know to vote no?" Grassley said.

Other senators went even further in criticizing the Democratic demands.

"It's just amazing to me they make such a farce of this," said Sen. Orrin Hatch, R-Utah. He urged the Senate not to continue "down this partisan, picky, stupid" path.

Sen. Thom Tillis, R-N.C., said the documents already being sought would stack as high as the Capitol dome. Sen. Mike Lee, R-Utah, said they would stretch 11.9 miles (19.2 kilometers) — "Kavanaughtical" miles, he called them.

At the White House, press secretary Sarah Huckabee Sanders backed up the GOP senators: "We don't want a taxpayer-funded fishing expedition."

The paperwork battle was always expected to be the potential tripwire for the Yale-educated Kavanaugh, whose long record in public service comes with a document trail that could provide insight to his views on key issues.

His job as staff secretary has been described as the president's inbox and outbox, touching more than 1 million pages that passed the commander in chief's desk — including prominent Bush-era issues like the detention and interrogation of terror suspects.

Separately, Democrats have become particularly concerned about Kavanaugh's views on the special counsel law, which were shaped by his experience on Kenneth Starr's team investigating President Bill Clinton.

The issue has become more pressing as Trump tweets, as he did Wednesday, that Attorney General Jeff Sessions should end special counsel Robert Mueller's probe of Russian interference in the 2016 election. Kavanaugh had earlier suggested such investigations can impede a president's ability to govern.

As Kavanaugh visits with senators on Capitol Hill — he has met with 47 senators so far, all but one of them Republicans — questions about his approach to the special counsel law have been raised, senators said.

Tillis said Kavanaugh did "a good job" in discussing the issue.

Grassley said it remains his belief that Mueller should be allowed to finish his probe.

Democrats say the additional documents they are requesting are crucial to understanding all aspects of Kavanaugh's background.

But the dispute is also a way to slow the GOP's drive to confirm Kavanaugh and potentially build opposition. Protesters flooded some halls in the Capitol complex this week as Kavanaugh went door-to-door meeting with senators.

"Getting the documents is especially important," said Sen. Ron Wyden, D-Ore. He pointed to the recent confirmation battle over Ryan Bounds, whose judicial nomination was derailed after new writings were unearthed from his college days.