The WNBA might be the American sports league with the most potential for growth. It’s hard to imagine the NFL or NBA getting that much bigger than they already are, and although Major League Baseball seems to have mostly leveled its decline, the sport isn’t winning new converts by the millions. Soccer, meanwhile, has been five years away from dominating the nation’s sports landscape for several decades now. But women’s basketball is a different story. The game is steadily minting new superstars at the college level. Last spring, for the first time ever, the women’s NCAA championship game drew more viewers than the men’s final. In the pros, one of the major challenges the WNBA has faced is that there simply aren’t enough teams to ensure…