As of the 2000 census, Sacramento had 407,000 or so, which, if my math is correct.. let me see... carry the two... yes, yes, it seems 407,000 is still less than 1.5 million. :-)
I went to census.gov... and yes, as of the 2000 census, Sacramento's population = 407,018. As of 2003, it's at 445,335.
San Antonio's population: 2000 = 1,144,646, 2003 estimate = 1,214,725. If you count people in outlying areas it adds up to about 1.5 million.
Here are some more cities that have NBA teams and are smaller than San Antonio:
Indianapolis, IN (783,438)
Milwaukee, WI (586,941)
Minneapolis, MN (373,188)
New Orleans, LA (469,032)
Portland, OR (2003 estimate = 538,544)
Salt Lake City, UT (179,894)
Do you still think San Antonio's a small town?