Well Joel, all I can say is, it's possible. To give you a write up on everything about fighting Poa could almost constitute a whole book at this point (almost like the already published book about managing Poa as a desireable turfgrass!). It's a fine line almost every course in California has to encounter at some point: to put alot of resources and effort into preventing and eradicating Poa, or to just give in, hold it off as long as you can, but eventually start managing it just like the rest of your grasses.
I can tell you at least at Empire Ranch, and many other courses I've visited (see Sonoma GC, SFCC, among others) the best chance you have is to start from grow in, or from a complete rennovation. Most attempts to interseed into existing stong Poa stands hasn't worked very well. But if you start out with a nearly pure stand of Rye or Bent, whatever you have, the right combination of water, fertilizer and just a touch of chemicals can actually be very successful at keeping Poa at bay. And for those that cherish the qualities of those other grasses as opposed to the yellow-green color and afternoon bumpy nature of Poa, many will go to great lengths to do whatever they can to keep Poa away from their course.
I have never seen 100% control, but I have seen 80-90% and that's pretty good as far as the golfers are concerned.
Two main points for fighting Poa:
(1) Poa, like any plant, grows and thrives where conditions for its needs are most favorable (right kind of soil, moisture, sunlight, etc.). If you can manage the conditions in such a way as to make them more favorable for another kind of grass, you've achieved part success.
(2) Poa in these cases is treated as a weed. And as with any other weed, the absolute BEST defense is a dense, healthly stand of your desirable turfgrass. If you can sod in/grow in a dense stand of your desirable grass, and KEEP it dense (that's the key), there is little room for Poa to compete.
Obviously it all sounds simpler in theory than it actually is in practice.