LA Times: As outlying sagebrush was quickly devoured by starter homes and chain stores, Las Vegas began grappling with the kinds of problems that long have vexed California: Crowded classrooms. Packed freeways. Not enough water. Immigrants who struggle to learn English. Rising poverty. Similar issues have bedeviled the areas around Phoenix, Denver, Salt Lake City and Albuquerque. By 2040, Las Vegas and its four brethren will grow by nearly 12.7 million people. While a booming population …