Yes, port can be drunk as a dinner wine, even as the main course. Of course only some ports are good enough to be able to be drunk that way, some are too "raisiny" but that is more a flaw than a port characteristic imho. Of course the classic duck wine is Banyul (which is somewhat port-like). The richer the food, the better the wine and the meal. Of course this style of dining is to be indulged in rarely (once or twice a year) if you value your liver.