WRONG! They intentionally did not declare a democracy, rightfully recognizing that it would lead to anarchy. They did declare a Democratic Republic form of government.
Is this a public school thingy? (Respectfully teasing!)
As long as we're niggling, they didn't even do that. Here is what they did do:
The United States shall guarantee to every state in this union, a republican form of government
No mention of democracy at all. Legislatures chose Senators. Electors chose the President and Vice President. The Execituve chose the Judiciary, with advice and consent. Only the House was to be, strictly speaking, democratically elected.