Exactly.
Murder is not a social issue. The DoI observes a right to life.
Congress shall not infringe ownership & possession of weapons.
"Gay marriage" isn't marriage, however you cut it. Two guys can't make a baby, impossible, no hope, period, full stop.
Congress may promote the general welfare, but not by robbing Peter to pay Paul.
Ordering Peter to pay Paul is also not tolerable.
I can arrange my own retirement plan, thank you very much.
Preventing the federal gov't from meddling in these social issues is also the core of conservatism; anyone (Rudy) who does meddle contrary to the above points rapidly loses his "conservative" mantle.
And actively ensuring the gov't does not meddle in social issues must not be confused with meddling in social issues.
But states were designed to adjucate social issues.
Just so long as they have a democratic form of government, they are empowered to do whatever they want.
Since Rudy was the mayor of a city, not president of the country, he had authority over a different set of issues. He instructed the police to arrest disorderly vagrants, because that is what the voters wanted. The voters had the full authority to elect a city government that gave disorderly vagrants free money from the public treasury, but they had already tried that and found it unsatisfactory.