[Originally a comment from this story. Copied here because it got rather long.]
As a mathematician/physicist who is gradually turning into a lawyer/politician (in the UK) the lack of scientists in high political places doesn't surprise me at all - the two groups have some fundamentally different ways of thinking about things.
In science, in general, everyone is working towards the same goal. While we all want funding and there is only a certain amount to go around, we're all trying to find some sort of "truth" about the little area of reality we study. If someone comes along and disproves one of our theories, we might feel a little upset, but we can keep going somewhere else. Furthermore, individually, we aren't important - what matters is the theory. A theory should (in theory...) be equally valid whoever suggests it, should be able to stand on its own merits and a scientific attack on a theory (which should be encouraged, of course) is only an attack on the theory, not the theorist.
In law, everything is very adversarial (in the UK and US, and similar common law countries) - there is a prosecution (or claimant/plaintiff) and a defendant and each side is trying to discredit the other. Neither side is really interested in the facts, but is interested in proving their case. Everything is personalised (even if it shouldn't be) and cases can easily come down to the advocates, not the facts. Politics is fairly similar (due to involving lawyers); it doesn't matter what a policy is, what matters is who is pushing it and how - a terrible, unscientific policy (banking regulation, tax breaks for the rich, ID cards, spending cuts, student tuition fees etc.) can be forced through by being well-marketed. Most of the population has little idea what the person they're voting for's policies are, and even less what they are likely to actually do - they vote for the person or the party. If a policy becomes particularly unpopular, it can end up bringing down the politician attached to it.
Another key difference comes from the "burden of proof". In science (in general), if someone makes a claim of sorts, it is up to them to prove it; challenging is expected and encouraged and it is up to the theorist to bring evidence. In theory, a theory is never proven (outside mathematics), merely accepted as likely based on the evidence. Contrast this with law or politics - here, if someone makes a claim, and another challenges it, it is expected in politics, or required in law, that the challenger make the case and present evidence; thus a politician can get away with all sorts of ridiculous claims, ("ID cards will stop terrorism", "copyright infringement is killing kittens" etc.) provided disproving them is problematic, or any challengers aren't given a platform to speak.
[This leads to all sorts of problems; consider the classic (if hypothetical) case where a homoeopath comes along and makes the claim "my homoeopathic treatment can cure the cold according to studies". The scientist says "that's complete rubbish, prove it." The homoeopath then cries defamation and says "Aha, no - you have to disprove it!". Suddenly the scientist is in a libel lawsuit, costing several years and millions of Â£s. The area of global warming is a similar story; the science is mostly done, but politicians will still argue, spreading FUD.]
FUD (fear, uncertainty and doubt) is also an interesting difference. To a scientist, actively creating fear, uncertainty and doubt should be considered abhorrent (while doubt is good, it should be lessened with time, not increased). To a lawyer or politician, it is one of the fundamental tools; in fact it is the primary weapon of a defence lawyer, whose job is to create as much doubt as possible.
This has turned into slightly more of an essay than planned, but I shall carry on anyway...
The legal and scientific approaches are so different that it can obviously be troubling for either side to deal with the other (I am treating legal and political together - while they aren't that closely aligned in the UK, from what I understand in the US the gap is smaller due to some legal officials being elected, and the costs involved with running for office). Sadly, it seems that our societies are putting more faith in lawyers and politicians than in scientists (just look at films, TV series etc. - a classic example being the start of Stargate Universe where [spoiler warning] the noble, honest politician sacrifices himself to save the mission, while the evil, scheming scientist is just that). It is little wonder to me that we're digging ourselves further and further into a great hole of ignorance, despair and superstition - when you put your faith in the messenger not the message, that is a risk you run.