I love a cold Presidente. Its pisswater, but a crisp, bitter pisswater that is great in the summer and is more loved, it seems, by the people of the DR than any other national beer is loved by its constituents. In the DR, Presidente provides coolers (like Old Style provides signs here) that keep the beer just above frozen. Bien fria.
Anyway, Sam's used to carry it regularly and cheap at a time the US distributor was making a push to other "Latino" markets, maybe 5-6 years ago. (Several of the counter ladies at Sam's are (were) Dominican, BTW, as I discovered when buying Presidente.) They have not had it in a long time. It appears from time to time at La Unica, as mentioned, but it remains very hit-or-miss. So too in liquor stores in and around Humboldt Park and Logan Square, for obvious reasons.
I find the Guatemalan Beer Gallo to be similar and good. Most always on hand at La Unica.