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

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

—Benjamin Franklin

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

Can we see your heels?

—John Adams

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

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.

What advice would you give to a father of a teenage daughter on how to protect her from boys, dating, and social media? How should fathers discuss these topics with their daughters?

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.

—Alexis de Tocqueville

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.

End of an Era: Landsat 7 Decommissioned After 25 Years of Earth Observation - USGS (.gov)

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.”

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.

Why? Try these on for size:

Why can't NASA just bite the bullet and launch a plainly simple mission, audited by flat earther peers start to finish that definitively proves to even the smallest minds that the earth is an oblong spheroid, and not flat?

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.

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

—Thomas Jefferson

Trump airs frustrations with Xi and Jerome Powell over elusive economic goals - NBC News

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