The Supreme Court. (Pablo Martinez Monsivais/AP)

A coalition of civil rights groups, Democratic lawyers and the Obama administration has scored significant victories in overturning strict voting laws, highlighting how the death of Justice Antonin Scalia has removed the Supreme Court as a crucial conservative backstop for such measures.

As the presidential election approaches, the challengers have rung up wins against their two top targets. Texas and North Carolina are now under judicial order to shelve comprehensive voting laws, passed by Republican legislators, that appeals courts said discriminated against African Americans and Hispanics. In Wisconsin, meanwhile, a federal judge has begun overseeing efforts to make it easier for those lacking the state’s required ID to cast ballots.

With the Supreme Court at an ideological impasse and Senate Republicans refusing to allow hearings for President Obama’s nominee to the court, Merrick Garland, the final state rules for elections throughout the country are likely to be set in a variety of decisions by state courts and lower-level federal judges.

“We’ll be in hand-to-hand combat the rest of the way,” said Marc E. Elias, a Washington lawyer who has filed many of the suits challenging the laws and whose firm represents Democratic presidential nominee Hillary Clinton and a host of party officeholders and committees.

Attorney Marc Elias exits a courthouse in Arizona after a hearing in a lawsuit against the state over voting rights. (David Jolkovski for The Washington Post)

While state officials have suffered legal setbacks in North Carolina, Texas and Wisconsin — where federal courts restored some early-voting opportunities, seen as beneficial to African Americans — only North Carolina has tried to get the Supreme Court to put the lower-court decisions on hold.

But without Scalia, who died in February, to provide a fifth vote for conservatives, the high court deadlocked 4 to 4 and the lower-court rulings remained in place.

A variety of lawsuits remain in play throughout the country. Outstanding issues include rules about the handling of absentee ballots; a question of whether proof of citizenship can be required for voter registration; challenges to purges of inactive voters; and methods for counting the votes of those who are registered and eligible but mistakenly cast their ballots in the wrong precincts.

These issues are all part of an intense legal battle in which even a slight advantage for one party could prove decisive in a close contest.

One hot spot is Ohio, a crucial battlefield in the presidential election and a state with a history of voting issues and litigation.

Elias’s efforts there were unsuccessful. The Ohio Democratic Party is trying to convince the courts that they should add back the “Golden Week” eliminated by the Republican-controlled legislature — a short period in which people may register and vote at the same time.

A district judge agreed with the Democrats. But the U.S. Court of Appeals for the 6th Circuit overruled that decision and said Ohio already provided more early voting than the vast majority of states.

Elias has asked the Supreme Court to intervene. But he and election-law experts agree it will be difficult to win the majority of justices needed to put on hold any appeals-court decision when the high court is divided evenly among liberals and conservatives.

The “question of how one writes a brief (emergency or otherwise) to capture five justices on an ideological, evenly divided court remains a great one to consider,” Richard Hasen, a law professor at the University of California at Irvine, wrote last week after the court’s action in the North Carolina case.

Michigan is also at the high court looking for that formula.

After decades of use, the state legislature eliminated straight-ticket voting, which allows a person to vote for all the candidates of a party with one motion. Democrats have opposed the GOP-sponsored law because it would slow the voting process and create longer lines, disproportionately affecting African American voters who favor straight-ticket voting.

A district judge blocked the Michigan law, and an appeals court has refused to reconsider that judge’s decision.

Michigan Attorney General Bill Schuette (R) has turned to the Supreme Court and asked for quick action on behalf of the law. In his filing, Schuette says that Michigan, by barring straight-ticket voting, is simply trying to do what 40 other states have already done.

“Having voters actually cast a vote for their chosen candidate — rather than blindly voting for all candidates of a party — is the very act of voting, so it cannot rationally be characterized as a burden on the right to vote,” he wrote.

States won many of the battles that preceded the general election two years ago because the conservative majority on the Supreme Court refused requests to stop their implementation.

But since then, lower courts have become more critical. They have increasingly looked more closely at the intent of legislators changing election laws and whether the changes were made to disadvantage minority voters.

“I think the winds are changing with regards to voting rights in the courts,” J. Gerald Hebert, executive director of the Campaign Legal Center, said in a recent interview.

After the Supreme Court approved Indiana’s voter-identification law six years ago, Hebert said, most state laws requiring a photo ID were thought to be safe from challenge. The Indiana law, unlike those in some subsequent cases, was not shown to affect racial groups differently.

In the recent cases, however, plaintiffs have been able to convince judges that some state laws were designed to discourage turnout by some groups or did not contain accommodations for those who lacked documentation, such as birth certificates, needed to get the photo IDs.

The judges who ruled that Texas and North Carolina could not implement their laws, for instance, said requiring a photo ID was not the problem ; the problem was that the states required IDs that were most likely to be held by whites — such as driver’s licenses and passports — and disallowed those that African Americans were more likely to possess, such as state government employment IDs or college identification cards.

Sherrilyn Ifill, head of the NAACP Legal Defense and Educational Fund, said in a recent interview that trials, with expert witnesses and voluminous records, were instrumental in rebutting the states’ rationale that the laws were needed to combat voter fraud and restore voters’ confidence in the election.

“We always believed if we had a chance to try these cases, we could show that the rhetoric did not match the record,” Ifill said.

The state officials whose laws have been invalidated say the real change has come in the makeup of the judiciary after nearly eight years of Obama’s nominations. Legislative leaders in North Carolina, for instance, noted that the three-judge panel that ruled that the state’s law intentionally discriminated was composed of judges nominated to the court by Democratic presidents.

“We can only wonder if the intent is to reopen the door for voter fraud, potentially allowing fellow Democrat politicians like Hillary Clinton . . . to steal the election,” state Senate leader Phil Berger and House Speaker Tim Moore, both Republicans, said in a statement.

And after the Supreme Court refused to reinstate the law, Gov. Pat McCrory (R) blamed the court’s “four liberal justices [who] blocked North Carolina protections afforded by our sensible voter laws.”

But Texas’s law was found discriminatory by a 9-to-6 vote of the full U.S. Court of Appeals for the 5th Circuit, known as the most conservative in the country. The majority was composed almost equally of judges nominated by Republican and Democratic presidents.

It is important to note that the Supreme Court has ruled only on emergency filings by states that want to implement their laws or plaintiffs who want to block them, since there is not enough time before the election for the justices to consider their actual merits.

But eventually, the justices will have to confront whether the new laws comply with the court’s precedents — or even whether those precedents should remain.

“This will ultimately have to be reviewed by the Supreme Court,” Elias said. “There will be a ninth justice at some point.”