Mod parent up. If 3 people just keep citing each other circularly (avoiding self-citations), the whole ranking collapses because all their papers will be artificially inflated. Accounting for this is quite hard because it will involve distinguishing between natural clusters (of top researchers working on a common topic) or citation gamers (aiming to boost their citation counts). Also, note in the TFA a graph with a parameter "d". That is basically slop. The authors simply changed the d until they could get a match for Nobel winners. Once you know what the answer ought to be, it's easy enough to manipulate a parameter like this.

There are serious differences in the world-view between the two candidates.

Two examples:

(1) Obama wants to improve science, technology, engineering and mathematics (STEM) education by broadening its scope beyond just science and engineering majors:

All American citizens need high quality STEM education that inspires them to know more about the world around them, engages them in exploring challenging questions, and involves them in high quality intellectual work. STEM education is no longer only for those pursuing STEM careers; it should enable all citizens to solve problems, collaborate, weigh evidence, and communicate ideas.

whereas McCain sees science as being for geeks only. He wants more geeks, so the rest of the country don't have to bother their pretty heads while getting law and business degrees:

The diminishing number of science, technology, engineering and math graduates at the college level poses a fundamental and immediate threat to American competitiveness. We must fill the pipeline to our colleges and universities with students prepared for the rigors of advanced engineering, math, science and technology degrees.

(2) Obama sees technology leadership as being essential to national security:

It's essential to create a coherent new defense technology strategy to meet the kinds of threats we may faceâ"asymmetric conflicts, urban operations, peacekeeping missions, and cyber, bio, and proliferation threats, as well as new kinds of symmetric threats.

whereas McCain sees national security as essentially just military superiority:

As President, I will strengthen the military, shore up our alliances, and ensure that the nation is capable of protecting the homeland, deterring potential military challenges, responding to any crisis that endangers American security, and prevailing in any conflict we are forced to fight.

For more contrasts, see my blog post