No. On the Federal level, it's a great republic. I'm paraphrasing, but I believe George Washington said that democracy is 51 wolves deciding to eat 49 sheep. Part of the purpose of the US Constitution is to protect the right of a minority (regarding free speech, religion, political opinion, etc.), despite the demands or views of the majority.
On the state and local level, there are more things that are considered democracy, with varying degrees of importance: ex. voting on issuance of bonds for a particular project, amendments to state constitutions, and things such as legalization of marijuana.
Where do I sign?
America is becoming a democracy, unfortunately. But its still a great Republic. The greatest Republic ever created so far.
