Justice Alito, who wrote the majority opinion, in this case explains their decision:
Despite all this evidence, municipal respondents argue that Members of Congress overwhelmingly viewed §1 of the Fourteenth Amendment as purely an antidiscrimination rule. But while §1 does contain an antidiscrimination rule, i.e., the Equal Protection Clause, it can hardly be said that the section does no more than prohibit discrimination. If what municipal respondents mean is that the Second Amendment should be singled out for special—and specially unfavorable—treatment, the Court rejects the suggestion. The right to keep and bear arms must be regarded as a substantive guarantee, not a prohibition that could be ignored so long as the States legislated in an evenhanded manner.
While Alito and the 4 other judges that voted for the ban pointed out that the Second Amendment should be incorporated for local governments just as it is with the federal government.
The 4 dissenting judges were arguing more for an “incorporation for me, but not for thee” view of the second amendment, as Justice Scalia portrays in the dissenting opinion:
The next constraint JUSTICE STEVENS suggests is harder to evaluate. He describes as “an important tool for guiding judicial discretion” “sensitivity to the interaction between the intrinsic aspects of liberty and the practical realities of contemporary society.” Post, at 24. I cannot say whether that sensitivity will really guide judges because I have no idea what it is. Is it some sixth sense instilled in judges when they ascend to the bench? Or does it mean judge sare more constrained when they agonize about the cosmic conflict between liberty and its potentially harmful consequences? Attempting to give the concept more precision, JUSTICE STEVENS explains that “sensitivity is an aspect of a deeper principle: the need to approach our work with humility and caution.” Ibid. Both traits are undeniably admirable, though what relation they bear to sensitivity is a mystery. But it makes no difference, for the first case JUSTICE STEVENS cites in support, see ibid., Casey, 505 U. S., at 849, dispels any illusion that he has a meaningful form of judicial modesty in mind.
JUSTICE STEVENS offers no examples to illustrate the next constraint: stare decisis, post, at 25. But his view of it is surely not very confining, since he holds out as a “canonical” exemplar of the proper approach, see post, at 16, 54, Lawrence, which overruled a case decided a mere 17 years earlier, Bowers v. Hardwick, 478 U. S. 186 (1986), see 539 U. S., at 578 (it “was not correct when it was decided, and it is not correct today”). Moreover, JUSTICE STEVENS would apply that constraint unevenly: He apparently approves those Warren Court cases that adopted jotfor-jot incorporation of procedural protections for criminal defendants, post, at 11, but would abandon those Warren Court rulings that undercut his approach to substantive rights, on the basis that we have “cut back” on cases from that era before, post, at 12.
The dissenting judges are letting their personal political views get in the way of their decision in this case. Their aversion for guns is the only reason why they are would go against McDonald here. There is no legit legal reason for incorporating every other amendment, including illegal search and seizure, freedom of press, and due process, but not the right to bear arms. Blanket handgun bans will very soon be nothing short of a bad memory.