Background on interpretation
Just as a background to Armageddon... there are several schools of thought as to how you interpret a constiutional or statuory provision, and we may see them all in play tommorrow. Note that a judge may use one of them, or a mixture, or explain his/her position by saying it's justified under more than one. One approach you'll rarely see is "living constitution." It may be the underlying thought, but to come out and say it is a bit too obvious. Main approaches:
1) Textualism (a favorite of Scalia). The words mean what they say, and unless hopelessly muddled, there is no reason to study the writer's intent. After all, the legislature or the people voted on the words, not on the drafter's intent.
2) Original purpose/understanding (a favorite of Thomas, and well suited to combine with textualism). On a constitutional level this started out as original intent -- what did the constitutional convention, of the First Congress, intend to do? Given limited records, this can be difficult to judge, but we must do our best to carry out their intent. (As Gene Volokh points out, if you want to adjust or repair a machine, you go to the manufacturer's manual to understand how it was meant to work. The Framers created a very good machine for manufacturing laws).
This evolved into original public understanding. After all, it was the people of the US as a whole who gave life to the constitutional provisions, via convention or legislative ratification. Let's look to what they understood things to mean. The records of the constitutional convention and the Framer's private letters weren't available to the people then, and are accordingly less important (except to the extent they, like anyone's letters, suggest what people in general thought). Now we can consider newspaper articles, letters, and even things written after the ratification, so long as it's unlikely that popular views as to meaning had changed.
3) Pragmatism. Don't sit there with a grammar book trying to parse the words. Figure out what the drafters meant to do by it, and construe their words so as to make that outcome more likely. They probably weren't all that careful about word choice anyway. They just said "freedom of speech" and didn't bother to explain what exceptions there are, did they mean the 1776 British idea of it, something much broader, or what?
As one fellow said--you can argue for any of these standards, and maybe the most we can expect is that a judge will stick to one or a fixed combination of them, and not be textualist when it yields a desired result, then switch to pragmatism in a different case because that gives the desired result.
(I leave off other approached, such as Prof. Levinson's argument that we have an unwritten consttution as well as a written one, the unwritten may add to our freedoms but not negate them, since these aren't likely to play a role in Heller).
Personal feelings -- they can play a role in all of this. I suspect at a subsconscious level. You're apt to be enthusiastic about rights you personally value. They play a much bigger role when you get down to what is allowable regulation. How strict is the standard? That's entirely up in the air, with no hard rules. If it's the strictest standard, what is a "compelling" government interest, and does this properly address it? Hard to make that judgment without be affected by your underlying beliefs that gun control is generally nice, or generally stupid policy. If you're on the Court and a porn case comes up, it's going to be hard to decide whether this particular movie is OK or not without being affected by whether you feel porn is sociallly corrupting, or is harmless, and whether you're hard to shock anyway.