It's not a dictatorship (yet), but consider this:
The overrepresentation of small states in the Senate and the Electoral College is undemocratic. Winner-take-all elections are undemocratic. The entrenched two-party system and the primary system are undemocratic. Gerrymandering is undemocratic. The seniority system (for congressional leadership posts) is undemocratic, and so is the excessive power of congressional leaders. Forcing candidates to compete by means of paid advertising is undemocratic. And the tendency to treat the President as a monarch is profoundly undemocratic.
It really bothers me that the "this is the greatest democracy the world has ever known" meme is so widely accepted, and so misleading.
If the U.S. were a democracy there would be considerably more representatives in Congress. Each district would be a geographically logical and relatively homogeneous area, and each district would send 2 to 5 representatives, using one of the proportional balloting schemes. In these elections nonparty candidates could compete (with some reasonable show of support by petition) along with party candidates.
If the U.S. were a democracy a presidential election would be a contest among six or a dozen credible candidates (again, party and nonparty) decided by proportional voting.
None of this will be easy to change, but that's not an excuse for not bringing out these facts at every opportunity.