Peter John-Baptiste, the Browns' chief communications officer, said HSG isn't anticipating or projecting 70 major, large-scale events. But because an enclosed stadium is capable of hosting many major events year-round, of many sizes, it could attract more than 2 million annual visitors to the region.

The endorsement of the region's leading chamber of commerce adds a new wrinkle to what has become a bitter battle between the team, the city, and the county.