When Judge John G. Roberts Jr. faced the Senate for his Supreme Court confirmation hearing in September 2005, critics sounded the alarm about his longstanding skepticism toward the 1965 Voting Rights Act, which many view as crucial to the political gains of Black Americans over the last half century.

“I fear that if Judge Roberts is confirmed to be chief justice of the United States, the Supreme Court would no longer hear the people’s cries for justice,” Representative John Lewis, the civil rights leader from Georgia, said in urging the Senate Judiciary Committee to reject the nomination.

Judge Roberts was easily confirmed by the Republican-controlled Senate despite pleas from Mr. Lewis and other civil rights activists. He went on to oversee the court in rulings that weakened the Voting Right Acts, compromising its decades-long role as a protector of minority access to the ballot box across much of the South. Mr. Lewis died last July, just months before Republican state legislatures enacted an onslaught of voting restrictions after the 2020 elections.

But it is not only those legislatures that Democrats see as their adversaries on election issues.

“We are also up against a Supreme Court that is keen on destroying our nation’s most consequential voting rights law,” Representative Terry A. Sewell, Democrat of Alabama, said this week during a Democratic call celebrating the anniversary of women’s right to vote.

While Mr. Lewis may be gone, House Democrats hope to keep his spirit alive by passing a bill bearing his name next week that they hope will offset what Speaker Nancy Pelosi has called “disastrous” and “shameful” decisions undermining voting rights by the Roberts-led court.

The John Lewis Voting Rights Advancement Act is one element of a two-pronged legislative effort by Democrats to protect minority voting rights. A much broader bill, the For the People Act, would impose an array of requirements on states to expand voting by mail and early voting along with extensive provisions on ethics, campaign finance and redistricting.

The bill named for Mr. Lewis is narrower and focuses on restoring the power of the Voting Rights Act. Both measures face a bleak future in the Senate, where Republicans are nearly unanimous in their opposition to them.

But Democrats, who control the evenly divided chamber with Vice President Kamala Harris’s tiebreaking vote, say they have not given up.

“Republicans refusing to support anything on voting rights is not an excuse for Democrats to do nothing,” said Senator Chuck Schumer, Democrat of New York and the majority leader, promising that Democrats would make the legislation a priority when they return after Labor Day.

Democrats are scaling back the broader bill to unite their party for coming votes. The Lewis measure already has the backing of all 50 senators who caucus with Democratic leadership, including Senator Joe Manchin III of West Virginia, the sole Democrat who did not endorse the For the People Act. He has also enlisted the support of a lone Republican, Senator Lisa Murkowski of Alaska, far from the minimum of 10 Republicans needed to overcome a filibuster.

The Lewis measure is aimed at reinvigorating the voting protections Democrats say were lost in two Supreme Court decisions that “gutted” the landmark underlying law — Shelby County v. Holder and Brnovich v. Democratic National Committee. The first, with a majority opinion written by Chief Justice Roberts in 2013, rendered moot a requirement that state and local governments with a history of imposing discriminatory voting laws receive “preclearance” from the Justice Department or a federal court in Washington before making changes to how people voted. The second, with a majority opinion written by Justice Samuel A. Alito Jr. last month, made it harder for minority voters to prove they were being discriminated against by asserting that the relevant part of the Voting Rights Act could be used only to strike down substantial voting restrictions, not merely inconvenient ones.

The new, highly detailed legislation would establish a contemporary formula for determining when governments must obtain preclearance for new voting rules and also abolish the standard set by Justice Alito’s opinion, which Democrats deplored as legislating from the bench. The bill would also require states to provide evidence of the voter fraud that the new laws are ostensibly meant to curtail.

Democratic officials involved in drafting the John Lewis act say it was carefully written to withstand constitutional scrutiny from the six conservatives on the court. But given the record of the court, and particularly that of the chief justice, satisfying the justices could prove difficult even if Democrats were to somehow get the measure to President Biden’s desk.

As a young lawyer in the Reagan administration in 1982, Mr. Roberts aggressively fought a bipartisan proposal to revise the expiring Voting Rights Act to counter an adverse Supreme Court ruling on the law in Mobile v. Bolden. In that decision two years earlier, the court weakened the law by requiring proof that the intent of a voting restriction was to discriminate — an exceedingly high bar. Democrats, with significant Republican support in Congress, proposed altering that new standard to one that required showing only that the result of a law was discriminatory.

In a series of memos that later became public, Mr. Roberts, then a special assistant to the attorney general, argued vehemently against the change. In one noteworthy memo, he said that violations of the Voting Rights Act “should not be made too easy to prove, since they provide a basis for the most intrusive interference imaginable by federal courts into state and local processes.” Congressional Republicans, fearing they would be branded as racists should they oppose the change, rejected that view. A compromise measure was approved on a strong bipartisan vote after breaking a Senate filibuster led by Jesse Helms, the archconservative from North Carolina.

At Judge Roberts’s confirmation hearing in 2005, Senator Edward M. Kennedy, Democrat of Massachusetts, pressed him on what Mr. Kennedy characterized as his “narrow and cramped, and perhaps even a meanspirited view of the law” given his comments in 1982. But Judge Roberts said he was merely arguing the position of the Reagan administration and his boss.

“I was a staff lawyer in the Justice Department,” he told Mr. Kennedy. “It was the position of the Reagan administration for whom I worked, the position of the attorney general for whom I worked, that the Voting Rights Act should be extended for the longest period of its extension in history without change.”

Eight years later, the chief justice wrote the opinion dismantling significant elements of the Voting Rights Act, saying that “things have changed dramatically” since the law’s adoption in 1965 and that governments should no longer be subjected to preclearance.

“The tests and devices that blocked ballot access have been forbidden nationwide for over 40 years,” he said.

Critics of that ruling and the subsequent one issued last month argue that the host of measures various states have passed in recent months make clear that Republicans have found new “tests and devices” to restrict access to the ballot. Those include provisions that make it harder to vote early or by mail, banning or restricting drop boxes, shortening early or absentee voting periods and giving more leeway to partisan poll watchers.

In his 2005 testimony, Mr. Lewis, who was badly beaten in a civil rights march in Selma, Ala., in 1965, suggested that the nominee did not grasp what it had cost to enact the voting measure in the first place.

“In 1965, Jurist Roberts was 10 years old,” Mr. Lewis testified. “He may be a brilliant lawyer, but I wonder whether he can really understand the depth of what it took to get the Voting Rights Act passed.”

“As many of you know, I gave a little blood on the Edmund Pettus Bridge,” he told the senators, referring to the site of the march in Selma. “But some of my friends and colleagues gave all they had, their very lives for the right to vote.”