The values that one would think a non-Christianist American conservative would hold most dear are a product of moral philosophy:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed....Brooks sagely reports that moral judgements are "rapid intuitive decisions" rather than the product of deliberation. Day-to-day, perhaps they are. But millions of Americans were persuaded by watching southern policemen club nonviolent demonstrators that segregation was wrong. Sit-in participants and freedom marchers were demonstrating a very clearly articulated moral philosophy (see Letter from a Birmingham Jail) that changed this country.
Perhaps Brooks finds it comforting to think that morality can be entirely explained by evolutionary biology. Conservatives often find it hard to acknowledge that human ethics advance over time - and to accord judges the authority to incorporate those advances into law.
Over time, however, Americans have been persuaded that slavery is wrong. That women deserve property rights, the vote, equal pay for equal work. That 60-hour work weeks for children are wrong. Now, we're in the process of concluding that marriage for gay people is right.
Those advances in morality were not (are not) "rapid intuitive decisions." They worked through public spectacle, and public discourse, ultimately informed by moral philosophy.
If evolution shapes our values, it shapes them through our reason as much as through emotion. Just as perception and evaluation can't easily be separated, neither can thought and feeling.