Ah right.

In Portugal in general use "propaganda" is definitelly just the political stuff whilst "publicidade" is definitelly just the commercial stuff.

Mind you, maybe before those two concepts were more merged: I know that in legal terms the political stuff is explicitly called "Propaganda Política" since I've done paphlet distribution for a political party here during election campaigns and the rules for putting "political propaganda" in people's mailboxes are different than for "publicidade".