Why is the word "democracy" not in the preamble of the US Constitution?

Why? Try these on for size:

[with republicanism being the rights-protecting form of governance afforded us by our Constitution]

To slaves: “You can forget your notions of freedom. We voted fair and square and your side lost.”

Why did my ex of 2 years move on so fast after he left me? Why does he act so cold towards me, and as if I don't exist?

—Benjamin Franklin

Majority-rules democracy is the way that majorities run roughshod over minorities, destroying rights and all ideas of equality under the law. No fair-minded person wants anything to do with democracy.

—Thomas Jefferson

Recently, I cleared my JP Morgan coding round. Next, I received mail for a video interview. What kind of questions are asked in this round? How do I prepare myself?

The republican is the only form of government which is not eternally at open or secret war with the rights of mankind.

I do not say that democracy has been more pernicious on the whole, and in the long run, than monarchy or aristocracy. Democracy has never been and never can be so durable as aristocracy or monarchy; but while it lasts, it is more bloody than either.

Meanwhile, when the Democratic Party formed in 1828, it was with a Tory outlook keen on robbing others of their rights:

Is it wrong that I picked to be a Christian (as a teenager/14-year-old) even with knowing all of the information about other religions/atheism?

To blacks: “You can’t drink from that water fountain… eat in this cafeteria… ride this bus… go to this school. We voted fair and square and your side lost.

In other words, our Founding Fathers and other Whig intellects of that time well understood that democratic methods are the surefire means to do serious damage to the rights guaranteed under republican self-government.

To Indians: “Pack up what belongings you can carry and start walking to Oklahoma. Your fertile lands are ours now. We voted fair and square and your side lost.”

What is the naughtiest fantasy that you've lived out?

—John Adams

—Alexis de Tocqueville

Another tendency, which is extremely natural to democratic nations and extremely dangerous, is that which leads them to despise and undervalue the rights of private persons.

Why does Russia and many parts of Eastern Europe strangely have a high percentage of female doctors and physicians (~70%)?

When the people find they can vote themselves money, that will herald the end of the republic.