Mathematicians rely more heavily on their written records than scientists in any other field. In physics, for example, each new theory is expected to provide a more accurate and broadly applicable approximation to reality. New theories frequently replace or even invalidate their predecessors. Consequently, old journals rapidly lose their value. In mathematics, however, once something is proved true, it remains true forever (assuming no error in the original proof). It is impossible to be expert in all branches of mathematics or even to know the proofs of every result you are likely to need in your work. It is a forgiveable - and often necessary - shortcut to assume the correctness of previously published results, without carefully checking each detail (but if you rely heavily on a result or need a variant, you ultimately end up learning its proof). Rapid scientific progress relies on intellectual specialization, which in turn requires trust in the refereed work of your predecessors (and contemporaries).
In politics too, most people do not have the time to become expert in every issue. From the feedback mechanisms required to understand global warmism to the importance of derivatives in providing grease to the gears of the economy, it is hard (impossible?) for most people to be well versed in the majority of issues facing our nation. Hence we all must rely on the deliberations of others; we cannot always check their 'proofs'. Unlike in mathematics, however, there is no refereeing process to check accuracy in politics. Most of us ultimately use party affiliation as a proxy for refereeing. We are most likely to believe the analysis of the political party whose past record and previous positions inspire the most trust in us.
Party affiliation alone is usually too broad to allow us confidence in the pronouncements of our copartisans. In addition to party, we rely on ideology. I am always amused by the attacks on ideologues as rigid and unthinking obstacles to progress. I suppose the definition of ideologue should be anyone whose principles are different from yours. If I know the principles driving the political positions of the person who is helping me take positions on the myriad of issues we face, then I am better able to trust his conclusions. Conversely, I distrust nonideologues. If the mavericks of McCain's ilk claim not to have fundamental principles guiding their economic decisions, what does? A desire for power? Popularity? Employment? I'll choose the principled ideologue every time.
Party affiliation has dropped dramatically in recent years. I hope the hordes of independents have the time and energy to research every issue, as they are unwilling to outsource their research to a political party. The rapid flipping of the independents from the far left of candidate Obama to the embrace of the small government tea parties, suggests, however, that the independents did not do their homework. The absence of any ideological mooring with its attendant party identification clearly led to gross errors. (The Republican choice of a presidential candidate without guiding principles didn't help either.) I suspect that the Obama administration will provide a valuable political education for independents. I hope that the outcome is that they will henceforth outsource to Republicans those research jobs they do not have time to complete for themselves; I hope that the Republicans will nominate enough principled candidates to deserve the job.