According to polybius, how democratic was the roman republic?

Polybius was a Greek historian. He thought that in the “democratic Rome” the only democratic element found in the Roman constitution was that of elected assemblies and the tribunes of working class. While others including magistrates, Senate etc. was occupied by the aristocrats. By exaggerating the democratic elements the Rome was presented democratic in the eyes of modern scholars. 

it's not the readmission