In Los Angeles, tens of thousands of immigrants and immigrant rights advocates marched on Saturday in one of the nation’s largest immigration protests since last May Day. Demonstrators widely criticized President Bush’s proposed temporary guest worker program and the recent raids on immigrant workers. President Bush is expected to reveal a new plan today. It would create a new visa category for undocumented workers, who could apply for renewable three-year work permits at a cost of $3,500. Then, in order to become legal residents, workers would have to return to their home countries, apply and pay a $10,000 fine. The proposal also prohibits temporary workers from bringing their families into the country.