The 2nd Amendment was designed to defend against the government eliminating civil rights and no longer representing "the People". As designed, it does not succeed in its purpose, as the types of firearms that are permitted would be useless against the government-controlled armed forces.
In addition, the 2nd Amendment muddies the waters in arguments for and against gun control, which should be about the impact of guns on self-defense versus crime.
Since it no longer helps serve the purpose that it was designed for, it should be repealed so that gun control can be argued on its true merits, that is, whether the presence of guns in American society causes an increase or decrease in crime, murder and accidental death.