LOS ANGELES — It is not uncommon for mayors of cities represented in major sporting events to make friendly wagers that might cost the loser some pride.

With the Los Angeles Lakers and Phoenix Suns beginning the Western Conference finals Monday night in the National Basketball Association playoffs, the mayors of Los Angeles and Phoenix turned the tradition into a political statement over Arizona’s controversial new immigration enforcement law.

The law, which makes it a state crime not to carry immigration papers and gives police broad authority to check the papers of people they stop, already had moved from the political arena to the sports arena. The Suns wore “Los Sunsâ€