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

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.

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

—Alexis de Tocqueville

Chesterfield man reverses diabetes after losing seven stone - BBC

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.

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

Why? Try these on for size:

A Single Stellar Flare Could Change a Planet’s Atmosphere in Just Days—Including Earth - The Daily Galaxy

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

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.

—John Adams

A common herb shows promise for boosting brain health and fighting Alzheimer’s - PsyPost

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.”

—Benjamin Franklin

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

Why is it after eating almonds when I’m occupied, I don’t feel mild itch, but as soon as I have nothing to do, I feel mildly itchy?

—Thomas Jefferson

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

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.

In Pictures: Jeff Bezos and Lauren Sanchez wedding in Venice - BBC

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.