WASHINGTON - The Senate Judiciary Committee is expected to portray two starkly different portraits of Attorney General nominee Alberto R. Gonzales as confirmation hearings begin Thursday His supporters are expected to emphasize the one depicting the nominee as an American success story: one of eight children of Mexican immigrants who spoke little English and raised their family in a home with no hot water or telephone. Gonzales eventually graduated from Harvard Law School. He became a legal adviser to President Bush when he was governor of Texas, a member of that state's Supreme Court and now White House counsel. His critics, both on the committee and among witnesses testifying after Gonzales' own appearance on Thursday, will portray him as a lawyer who made colossal misjudgments in supervising the administration's legal strategy for dealing with al-Qaida and other terrorist threats. Gonzales will be the first of Bush's second-term Cabinet nominees to face a confirmation test. Although few believe Gonzales is in danger of being denied confirmation, he may nonetheless face the most vigorous interrogation because of his role in overseeing internal legal memorandums that appeared to condone mistreatment, perhaps even torture, of detainees. The timing of the hearings has proved especially awkward for the administration. They are coming just after a new round of disclosures about the treatment of detainees held by the U.S. military in Iraq and at Guantanamo Bay, Cuba, and reports that the administration may hold detainees in Cuba indefinitely. Underlying all the debate about Gonzales' role in the treatment of detainees is a widely held belief that he might be nominated by Bush to the Supreme Court depending on the number of vacancies that occur in his second term. Even some of Gonzales' detractors say that they do not expect to prevent him from becoming the nation's 80th attorney general, as well as the first Hispanic holder of the office. Instead, they say they hope to lay down a record that will make it difficult for him to be confirmed to the Supreme Court.