(Bloomberg) -- The U.S. Supreme Court’s conservative majority may be ready to overturn a longstanding precedent for the third time in recent weeks -- perhaps foreshadowing the vulnerability of its rulings on abortion rights.The justices will rule as early as Wednesday on a business-backed bid to overturn decades-old decisions that give federal agencies broad power to say what their regulations mean.The case is one of eight rulings due before the justices’ term ends this week. The court also plans to rule on gerrymandered voting maps and the Trump administration’s bid to add a citizenship question to the 2020 census.Another precedent-toppling ruling would extend a pattern that already has liberal justices sounding alarms. They’ve hinted that the five conservative justices may be eyeing the landmark 1973 Roe v. Wade ruling, which legalized abortion nationwide.“Today’s decision can only cause one to wonder which cases the court will overrule next,” dissenting Justice Stephen Breyer wrote last month when the court overruled a 1979 precedent to say that states are immune from private suits in another state’s courts.“Well, that didn’t take long,” Justice Elena Kagan wrote 39 days later when the court overturned part of a 1985 ruling and said people could go directly to federal court to claim that a government regulation unconstitutionally took private property without compensation. “Now one may wonder yet again.”Both of those were 5-4 decisions, with Chief Justice John Roberts and the other Republican appointees -- Justices Clarence Thomas, Samuel Alito, Neil Gorsuch and Brett Kavanaugh -- in the majority.Ducking AbortionSo far, the court has largely sidestepped the explosive topic of abortion. In May, the court turned away Indiana’s bid to bar abortions based on a fetus’s race or gender or a risk of genetic disorder -- an appeal that could have raised new doubts about Roe. The justices did uphold a separate Indiana law requiring clinics to bury or cremate fetal remains.The court could provide new signals about its intentions on abortion this week. The justices are due to say whether they’ll consider Alabama’s effort to ban the most common method used for women in their second trimester of pregnancy.The court under Roberts has actually overturned precedents at a slower rate than previous courts, says Jonathan Adler, a constitutional law professor at Case Western Reserve School of Law. Before this term started, the Roberts court had issued only 13 rulings that overturned a precedent, according to data from the Government Printing Office, he says.But Roberts, who took his seat in 2005, has never had a conservative majority as reliable as the one he got when the Senate confirmed Kavanaugh to succeed the retired Anthony Kennedy.“It is certainly possible either that the court may become more aggressive going forward or that the cases in which the court reconsiders precedents will have a greater ideological uniformity,” Adler said.Adler is among those urging the court to overturn a 1997 ruling, Auer v. Robbins, that requires judges to defer to a federal agency’s interpretation of its own regulations, as long as its approach is reasonable.Business groups say that ruling, along with a related 1945 decision, leads to onerous and unpredictable rules and leaves companies vulnerable to penalties when an agency shifts its thinking. Defenders of the rulings say they give agencies flexibility to account for changing circumstances.Religion and GerrymandersThe regulation, property-rights and sovereign-immunity cases are among the four appeals this term that squarely asked the justices to topple at least one precedent.The fourth one split the court in an unusual way last week. The court had been asked to overturn a rule that lets states and the federal government file separate criminal charges over the same conduct without violating the Constitution’s ban on double jeopardy.The court refused on a 7-2 vote, reaffirming precedents dating to the middle of the 19th century. Alito’s majority opinion said the case for keeping precedents “grows in proportion to their antiquity.” An unlikely pair of justices -- Gorsuch and liberal Ruth Bader Ginsburg -- dissented.Three other cases have raised questions about precedents, though less directly. In backing hunting rights in Wyoming for the Crow Indian Tribe, a majority that included the four liberals and Gorsuch said an 1896 ruling had previously been “repudiated.”In ruling last week that a 40-foot cross could remain in a Maryland public intersection as a war memorial, a majority of justices criticized, without overruling, a 1971 decision that set up a three-part test for assessing whether government support for religion goes too far.And the gerrymandering cases could topple a 1986 ruling that said voting maps could be challenged as too partisan, though the justices in that case couldn’t agree on a standard for doing so. Paul Clement, the lawyer defending a Republican-drawn North Carolina congressional map, told Roberts during arguments in March that the court might need to overturn that ruling.‘Jolt to the System’At the center of it all is Roberts, who said in his 2005 Senate confirmation hearing that overruling a precedent is a “jolt to the legal system.” He has tended to take a multi-step approach toward questioning a precedent, signaling concern in a preliminary case before voting to overturn it altogether.“His favorite methodology seems to be to essentially chip away at cases in various steps so that the day that the case is actually overruled it’s really not even news, it’s been coming for a couple of years,” Clement said last month at a symposium co-hosted by the conservative Heritage Foundation and Bradley Foundation.Writing the majority opinion in the property-rights case last week, Roberts said the 1985 Williamson County v. Hamilton Bank ruling relied on “exceptionally ill-founded reasoning,” had been repeatedly criticized by justices over the years and had proven “unworkable in practice.”It’s still too early to judge how Roberts will act toward precedents now that he has a stronger conservative majority, Adler said.“Like a lot of people I’m curious if the chief is going to become more aggressive, but I’m not willing to say that we can be sure of that yet,” said Adler.To contact the reporter on this story: Greg Stohr in Washington at gstohr@bloomberg.netTo contact the editors responsible for this story: Joe Sobczyk at jsobczyk@bloomberg.net, Laurie Asséo, John HarneyFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.