The critics. BY JONATHAN D. SALANT and KATE ANDERSEN BROWER Bloomberg President Barack Obama told a group of Democratic Party donors in San Francisco he’s determined to outlast his critics to move ahead on his agenda, including revamping the health-care system and financial regulations. “Some of our opponents think they are going to wear us down,” Obama said at a fundraiser for the Democratic National Committee last night at the Westin St. Francis Hotel in San Francisco. “I’m not