Ron Brownstein hails the genius of Rudy Giuliani in calling for "federalism" as the solution to "social issues such as gay rights and gun control" which, according to Brownstein, "divide America so sharply largely because no one has found a single solution for them equally acceptable to both churchgoing conservatives and secular liberals." The possibility that Giuliani endorses a federalist approach to these issues as rank political opportunism doesn't seem to be on the table.
Be that as it may, this is mostly nonsense. Some issues are genuinely local in nature, and gun control has many truly local characteristics. "socially conservative and liberal states to each set rules that reflect the prevailing values inside their borders. But "gay rights or aspects of abortion" aren't like that. If it's wrong to murder gay teens, then it's wrong in Iran and wrong in Idaho, and also wrong in Illinois. Not, fortunately, that Idaho seems likely to legalize killing gay teens but it was just a couple of years ago that Texas really was asserting in court its right to imprison gay men. And, conversely, if abortion is the mass slaughter of human persons then it's not okay in California but wrong in Kansas.
These questions are controversial because . . . they're controversial issues, not because they're decided at the federal level. Besides which, people don't actually come neatly apportioned into "blue" and "red" types. There are plenty of social conservatives living in New York and California, and plenty of liberals living in Texas. You could try to decide these issues on a neighborhood-by-neighborhood basis and you'd probably get something closer to politically homogeneous districts (you could use ZIP codes maybe) but that would make nonsense of the whole project.