Goodwin Liu couldn't speak English until kindergarten, but he went on to become co-valedictorian at Rio Americano High School in Sacramento, a Rhodes Scholar and a law professor at the University of California, Berkeley.

Goodwin Liu, a liberal favorite, has been named to serve on the 9th U.S. Circuit Court of Appeals.

Now he's under attack on Capitol Hill, where Republicans oppose his nomination to the 9th U.S. Circuit Court of Appeals in San Francisco.

Liu, the son of Taiwanese immigrants, is attracting far more attention than most judicial nominees. While his backers are excited by his solidly liberal credentials, some opponents fear Obama is preparing Liu for what would be a historic appointment: the first Asian American on the U.S. Supreme Court.

"He's by far the most controversial nominee that Obama has named and he's clearly being groomed for the Supreme Court, so there's every reason to give him a full dose of scrutiny," said Curt Levey, executive director of the conservative Committee for Justice.

Liu, now the associate dean of Boalt Hall School of Law at Berkeley, faces a difficult confirmation fight as the Senate Judiciary Committee prepares to take up his nomination.

A hearing is set for April 16, when senators will grill Liu and another Obama nominee: Kimberly Mueller, chosen to be a district court judge for the Eastern District of California in Sacramento.

Liu has advocated many liberal causes, supporting national health care, affirmative action, gay marriage and slavery reparations. He angered conservatives by testifying against Supreme Court Justice Samuel Alito. He has alarmed opponents by arguing that the Constitution should be interpreted based on "the evolving norms and traditions of our society," which conservatives say is code for judicial activism. His opposition to the death penalty drew fire from 42 of California's district attorneys, who sent a letter to the Judiciary Committee urging Liu's rejection.

Liu's record is not universally liberal: He has backed charter schools and private school vouchers, which are opposed by teacher unions. He has received words of praise from conservatives such as Kenneth Starr, the lawyer who investigated former President Bill Clinton.

Both of California's Democratic senators are enthusiastic supporters of Liu. Barbara Boxer called him an "inspired choice," while Dianne Feinstein said he's "as sharp as they come, with a kind demeanor and a good temperament."

Republicans are ready to make things tough for Liu. While promising to withhold final judgment on the nominee, Alabama Sen. Jeff Sessions, the top Republican on the Senate Judiciary Committee, said Liu was a former board member of the American Civil Liberties Union who was "far outside the mainstream of American jurisprudence."

"It seems to me that his judicial philosophy does not respect the American ideal of judges as neutral arbiters of the law," Sessions said. "I hope my initial impressions are wrong."

Liu declined to be interviewed, but he has plenty of supporters.

Edwin Prather, president of the Asian Pacific Bar of California, said GOP senators should not be challenging Liu, calling him a well-respected and highly qualified nominee.

"We need an Asian American on the 9th Circuit bench. We need Goodwin Liu on that bench," he said.

Vincent Eng, deputy director of the Washington-based Asian-American Justice Center, called Liu "a very exciting nominee" with exceptional qualifications.

"Those type of qualifications raise him to a higher level of scrutiny," he said, adding that Liu's record is not as controversial as it's being portrayed by conservatives.

Liu has already attracted a national following. Eng said more than 400 "Goodwin hearing parties" were scheduled last month in anticipation of Liu's appearance before the Judiciary Committee. Republicans used procedural tactics to delay that hearing for both Liu and Mueller, whose nomination has not sparked any similar controversy.

Liu, the child of two physicians, was born in Georgia and moved to Sacramento when he was 7, then graduated from high school in 1987. He served as a page in the U.S. House, which sparked an interest in law and politics, and he has degrees from Stanford University and Yale Law School. He served as a Supreme Court clerk in 2000 for Justice Ruth Bader Ginsburg and worked for the San Francisco Unified School District and the U.S. Department of Education during the Clinton administration.

While it's common for a president to tap an appellate court judge as a Supreme Court nominee, Liu would stand out among the nearly 175 judges because of his relatively young age. He's 39, and his supporters say that appointing him after a short tenure on an appellate court would give Obama a chance to shape the high court for decades.

Levey predicted the confirmation fight over Liu would be the biggest battle involving a lower-court judge this year. He wouldn't be surprised if it's a preview of an even bigger battle down the road.

But he noted that Liu has "zero courtroom experience" and should not be rushed into a judgeship.

For their part, Liu's supporters are focused on the present.

"The Supreme Court is sort of pie in the sky at this point," Prather said.