Looking at your site, I wonder if you wouldn’t mind my comments? I wonder if you would want to use alternate URLs? 
For example, instead of [1] what about [2]?  You could 301 redirect the former to the latter in case people wanted to access it directly by number. And though long, the latter would index better on Google and would be more easily understood by people who don’t remember by number. Further, if you wanted a shorter version, you could create a third version by coming up with a resonable short version of the title such as [3] (the nice thing is you don’t have to worry about new Federalists papers coming along to screw up your conventions!:) 

What’s more, I’d love to see you include these URLs at the top of your page with text like: “Each of these URLs will bring you to this page” I plan to advocate this in general for websites in the coming months.

Also, I notice you use the following fragment (using URI Template syntax): #a{article}s{section}c{clause}. Looking at that I don’t think many people would intuit that and hence might see it as just a generated fragment but one without meaning. I wonder if maybe you’d want to consider one of the following (of course changing means you’ll have to maintain both if you already have significant inward links):

#a{article}-s{section}-c{clause}
#art{article}sec{section}cla{clause}
#art{article}-sec{section}-cla{clause}
#article{article}section{section}clause{clause}
#article{article}-section{section}-clause{clause}

I know the latter is long, but it is very obvious what it means. The abbreviations “art” and “sec” are pretty clear, but maybe not “cla” unless you already know the terminology. If nothing else, seperate the letters with dashs

Now, that said, I’d also consider creating full URLs linking  directly to each article and section and clause), i.e. [4] or [5] (the slashes make using single letters in [5] a little more obvious than in the case of the fragment)

You could have a link to one of these URLs next to the heading that could open to a document showing just the text for this article/section/clause. To be clear, I don’t mean people would have to drill down to different URLs to read the constitution but instead if someone wanted to link directly to  article 1 section 8 clause 3 they could do so directly, AND be able to print just that clause.  Plus if linked correctly this could give you (slightly) more PageRank as each article/section/clause would link back to the higher level document.

I would (necessarily) advocate this level of effect for all documents, but your site has a series or rather significant documents so the effort put in will serve benefit long lasting; much more so than the average blog post. ;-)

[1] http://federali.st/2
[2] http://federali.st/concerning-dangers-from-foreign-force-and-influence/ 
[3] http://federali.st/foreign-dangers/
[4] http://federali.st/constitution/article-1/section-8/clause-3/
[5] http://federali.st/constitution/a1/s8/c3/