Jay Reding with a nice summary:

Mamet, however, hints at the real basis for conservatism. We can't cure war. We can't end all poverty. We can't make people into angels when they are not. The fundamental principle of conservatism can be roughly summed up into this: "sometimes life just sucks." Even if we could fix the problems that create war, poverty, racism and injustice to do so would be to have a society robbed of free will—because the root of all these problems are found in human nature itself. That's why Mamet rightly describes conservatism as the "tragic" view of human nature and liberalism as the "perfectionist" view of human nature. Conservatives recognize that there is no permanent solution for the ills of mankind—there are only advances which can ameliorate our conditions. We can't create heaven on earth, we can only fumble around as best we can.

We can, however, fumble creatively and sometimes radically in pursuing the intimations of any given moment. Conservatism doesn't mean the abandonment of imagination or change. It means an understanding of the impossibility of all ultimate fixes, and an ease in the current imperfection: a preference for current laughter over future bliss.