A constitutional republic is a form of democracy, not a democracy. More to the point however; since the U.S. uses a non-transparent voting process, it seems improper for anyone to refer to its state definition within democratic bound on any level.
Totalitarain Plutocracy maybe?
-Justhink
Some of the republic vs. democracy questions have been discussed in the past. You might wish to try the search engine.
One thread that seems useful to your endeavour.
You asked why do officials refer to the US as a democracy. That is a very different question than whether it is a democracy or not.
Most citizens think the US is a democracy. That’s fine by the officials. They’d rather not have to explain why it isn’t. And they’d rather that the populace believe it’s a democracy anyhow.
Whether politicians should use the word democracy or republic is so clear cut that the Staff Report on the subject ends with:
An argument for a plutocracy