As a former organizer in Las Vegas and someone who's read a bunch of histories of the city and the unions, you just need to read the history better. The union was established in the 1950s and the Teamster money was a big reason none of the hotels objects -- as long as they didn't try to unionize the guys counting the money in the cage where the mob was skimming the cash. By the 1970s, the whole town was unionized wall-to-wall; older workers told me that even the Denny's was once unionized. Then the corporate owners like Howard Hughes came in-- they were the ones who began trying to bust the union. There were major strikes in the 1970s and then, with even greater corporate ownership in the 1980s, a full-scale assault on the union in 1984. A number of the hotels were deunionized and new hotels began opening non-union. Workers all spoke fondly of the mob owners in comparison to the new corporate owners.
Enter the 1989 negotiations (where I came in as a young organizer)-- that was the do-or-die fight where outside organizers were brought in and the new organizing model developed to deal with the union. This was the rebirth of the union but not it's first time getting a foothold. In fact, it was just restoring the strength it once had back in the olden days.
-- Nathan Newman