Liberal-leaning justices and the gun-control movement were critical of the Heller decision, and Clinton herself said the court "is wrong on the Second Amendment," and a spokeswoman said Clinton believes Heller was "wrongly decided."
Heller's author, Justice Antonin Scalia, died in February, leaving the seat held by the court's leading conservative intellectual vacant. President Barack Obama nominated a moderate federal appeals court judge Merrick Garland on March 16 as his replacement, but Senate Republicans have stalled the confirmation process.
So if Clinton wins on Election Day, a 5-4 majority in Heller theoretically could turn into a 5-4 vote to overturn the precedent if a center-left justice takes the place of Scalia.
The prospect of such a reversal has gun-rights activists worried sick.
"If Clinton is able to pack the court with justices who believe our Second Amendment doesn't say what it means and mean what it says, then we'll lose the basis for our right to bear arms," NRA's website says. "If that happens, gun bans and other restrictions could both pass and stand up in courts throughout America.''
At its heart, the Heller case was about a District of Columbia law, a flat-out ban on handgun possession at home. In his opinion, Scalia took 64 pages to explain the grammatical construction of the Second Amendment and argue that it does, indeed, guarantee a gun-possession right. (Some legal scholars argued the Second Amendment applies only to the raising and arming of 18th-century-style militias, and does not confer gun rights on individuals.)
Scalia's opinion said that "like most rights, the right secured by the Second Amendment is not unlimited." Lawmakers at all levels and gun-control advocates have seized on those words to argue that Heller's Second Amendment-protections notwithstanding, state limitations such as New York's SAFE Act are permissible.
After Scalia's death, the NYSRPA president Tom King, said his group would not pursue a Supreme Court challenge of the SAFE Act. King cited the unlikelihood of a Scalia-less Supreme Court viewing an anti-SAFE-Act petition favorably.
The court has recently turned down several challenges to state and local laws banning military-style assault weapons. Justices didn't explain their reasoning in turning away the cases, but presumably the rejections were based on Heller's no-right-is-unlimited exception.
Adam Winkler, a law professor at UCLA who has written extensively on guns and the Second Amendment, believes the Clinton campaign is confused over Heller.
"Hillary is not helping her case by making these statements'' criticizing Heller, Winkler said. "She has a gun-control agenda but all its items are consistent with Heller. There's no reason to say Heller was wrongly decided.''
Favorable court decisions since Heller render the landmark case moot, said Leah Gunn Barrett, executive director of New Yorkers Against Gun Violence. Nevertheless, "if a local jurisdiction thinks it's important to limit guns in homes to ban suicide, unintentional shootings or guns being stolen, they should have the right to do so. If a jurisdiction wants to ban guns through its elected representatives, why shouldn't they?''
The flexibility in Heller has not led the GOP-controlled Congress to pass measures favored by Democrats such as expanded background checks for transactions at gun-shows and elsewhere, and the ``no-fly, no-buy'' law denying gun purchases to those on the government's terrorism watch list.
"It is Congress' job to act on the gun violence epidemic that takes 91 American lives every day, not the Supreme Court's,'' said Rep. Paul Tonko, D-Amsterdam. "Secretary Clinton could not unilaterally repeal the Second Amendment even if she wanted to, which she does not. Despite whatever fantasy Donald Trump throws the American public's way, she has said time and again that the Second Amendment must be protected."