Sure it does...but by whose standards? The graph you pasted is about as accurate as using a 12 gauge shotgun at 500 yards.
The website is very straightforward about the process of determining a plot on the graph. Still, one would have to look at it to determine the process they use.
For example, here is McCain's page from which that graph was gleaned.
http://www.ontheissues.org/John_McCain.htm
They divide political issues into 24 categories. As you can see, gun control is one of those issues. Let's use that as an example.
Strongly Favors topic 10:
Absolute right to gun ownership
(+5 points on Economic scale)
That figure was derived from these positions taken on gun rights:
Prosecute criminals, not citizens for gun ownership: Strongly Favors topic 10
Don't hold gun manufacturers liable for crimes: Favors topic 10
Opposes restrictions on assault weapons and ammunition types: Strongly Favors topic 10
Ban cheap guns; require safety locks; for gun show checks: Opposes topic 10
Voted against Brady Bill & assault weapon ban: Strongly Favors topic 10
Punish criminals who abuse 2nd Amendment rights: Favors topic 10
Repeal existing gun restrictions; penalize criminal use: Strongly Favors topic 10
Ban gun registration & trigger lock law in Washington DC: Strongly Favors topic 10
YES on maintaining current law: guns sold without trigger locks: Strongly Favors topic 10
YES on loosening license & background checks at gun shows: Favors topic 10
NO on background checks at gun shows: Strongly Favors topic 10
YES on banning lawsuits against gun manufacturers for gun violence: Strongly Favors topic 10
YES on prohibiting lawsuits against gun manufacturers: Strongly Favors topic 10
They assign the values based on this grading scale:
Strongly Favor = 2, Favor = 1, Neutral/Mixed = 0, Oppose = -1, Strongly Oppose = -2.
http://www.ontheissues.org/VoteMatc...a19=5&a20=5&i1=1&i2=1&i3=1&i4=1&p=23&e=70&t=4
Above is a more detailed explanation of their process.
Of course, a quicker, albeit less formal way to determine if their methods are indeed more accurate than a shotgun pattern at 500 yards would be to take a look at still
another candidate (or candidates) and see if the graph passes the "stupid test".
For example, we all "know" that Ron Paul is basically libertarian in his political leanings. We don't really need to look at a graph for this. We know. So it should come as no suprise when we pull him up and see:
Nope. No surpises there. Pretty much as we'd expect him to look.
But apparently, McCain's is not where some people expect him to be. Most likely because they've picked 3 or 4 pet issues and determined that McCain wasn't as conservative as he should have been...and is therefore no better than Obama or Hillary.
Of course, that is a simplistic and ridiculous opinion. An issue by issue study of their votes (i.e. McCain voted to confirm Roberts and Alito, Hillary and Obama didn't) eventually tears down such simplistic political notions.
But some people are more comfortable painting with BIG paintbrushes....