And one other issue still could be added: a review of President Trump's latest travel ban on immigrants and visitors from certain countries. The justices will consider next week whether to take that case.
On the gerrymandering front, the Supreme Court already has heard a challenge to the way Wisconsin Republicans drew legislative district maps. And last month it accepted a petition from Maryland Republicans to review the way that state's Democratic leadership redrew the lines of a congressional district held by a GOP congressman. Both of those cases involved charges of partisan gerrymandering.
The cases from Texas involve long-running disputes about whether Texas Republicans intentionally discriminated against minority voters when redrawing lines for congressional districts and the legislature in 2011.
A three-judge panel last summer found that two of the Texas congressional districts violated the Constitution and the Voting Rights Act, and were intentionally discriminatory. It found similarly that the state's legislative district maps were flawed.
It had ordered the state to redraw the lines in time for the 2018 elections. Instead, Texas asked the Supreme Court to put the rulings on hold until justices could review the ruling's merits.
The court agreed on a 5-to-4 vote in September, with the court's four liberals objecting. Both the congressional and legislative map cases are Abbott v. Perez.
The sales-tax case represents a consolidated effort by states to overturn a 1992 Supreme Court decision upholding a constitutional rule that barred requiring vendors to collect sales tax on mail-order sales unless the business had a "physical presence" in the state.
The rule has always been seen as controversial, and the explosion of Internet sales means state and local governments have lost billions of dollars in tax revenue. They say that the ruling is unfair to them and to bricks-and-mortar retailers within their borders that have no choice but to collect the taxes.
South Dakota took the lead, and told the court it was time to overturn the precedent, Quill Corp. v. North Dakota.
Companies now "can instantly tailor their marketing and overnight delivery of hundreds of thousands of products to individual customers based on their IP addresses; these companies can surely calculate sales tax from a zip code."
But online retailers that asked the court to stay out of the Internet sales battles disagreed. "The burdens will fall primarily on small and medium-size companies whose access to a national market will be stifled," said lawyers for Wayfair, Overstock.com and Newegg.
They said that the number of taxing jurisdictions in the United States is estimated at between 10,000 and 16,000.
And they contend that it should be up to Congress, not the courts, to remedy any problems that local governments say they have.
The petition "invites the court to assume a legislative role, supplanting Congress, the body to which the Constitution assigns responsibility for regulating commerce 'among the several states,' and which is actively addressing the issue," the companies said.
But Congress has struggled for years to come up with a plan, even though some online retailers have said that they would welcome a national remedy rather than deal with individual states.
The case is South Dakota v. Wayfair.
The SEC case is a technical issue that could affect how other regulatory agencies do their work.
At issue is whether the SEC's administrative law judges are employees or, because they wield significant decision-making authority, are "inferior officers" covered by the Constitution's "appointments clause."
Such officers must be appointed by the president, the head of a federal agency or by a court.
The case is brought by Raymond Lucia, a former California radio host and investment adviser known for his "Buckets of Money" strategy. His case was heard by an administrative law judge, and he received a lifetime ban from investment-related work.
It is also notable because it is another case for which the Trump administration's Justice Department switched sides. It says it now agrees with Lucia and others in the business community who say that the SEC's way of appointing the judges violates the Constitution.
The case is Lucia v. SEC.