The United States Supreme Court has held, in various rulings, that the Fourteenth Amendment extends the Federal Constitution to state governments, prohibiting states from violating the limitations on government action expressed in the Bill of Rights.
In June of 2008, in the case of District of Columbia v. Heller, the Supreme Court ruled that the Second Amendment protects an individual right to keep and bear arms from infringement by the Federal Government.
In January of 2009, Judge Sotomayor joined a Second Circuit opinion stating that it is “settled law” that Second Amendment protections are not incorporated into the Fourteenth Amendment…

It is settled law, however, that the Second Amendment applies only to limitations the federal government seeks to impose on this right.

And to the extent that Heller might be read to question the continuing validity of this principle, we “must follow Presser” because “[w]here, as here, a Supreme Court precedent ‘has direct application in a case, yet appears to rest on reasons rejected in some other line of decisions, the Court of Appeals should follow the case which directly controls, leaving to the Supreme Court the prerogative of overruling its own decisions.’”

1. If Judge Sotomayor believes that the Second Amendment is incorporated by the Fourteenth Amendment and therefore cannot be infringed upon by the states, or if she believes that the Second Amendment is fundamentally different from most other Constitutional protections afforded to individual Americans in the Bill of Rights and is not incorporated…
2. And, given her particular usage of the term “settled law”, if there are other areas where Judge Sotomayor believes that the Supreme Court might readily change what “settled law” currently says.