Alito, 55, is considered a conservative in the mold of Justice
Antonin Scalia. Alito is sometimes given the nickname "Scalito" -- a comparison to Scalia, who shares his Italian heritage as well as his reputation for conservatism and a strong intellect. He is a judge on the 3rd U.S. Circuit Court of Appeals in Philadelphia.

As nominee, he would replace White House counsel Harriet Miers, who withdrew her name from consideration last week under withering attack from conservatives within Bush's own Republican Party.

A conservative choice was bound to trigger a fight from Senate Democrats who want to see O'Connor replaced by a moderate justice like her.

Republican Sen. Jon Cornyn of Texas praised the choice, calling Alito "man of outstanding character, who is deeply committed to public service."

But Cornyn, who had supported a conservative choice, cautioned any potential Democratic opposition that, "It is important that the confirmation process be completed in a timely manner free of obstructionist tactics."

Although O'Connor has said she will remain until her replacement is named, the high court is nearly a month into its new session.

Aides were hoping that the Supreme Court nominee would give Bush a fresh start after one of the toughest weeks of his presidency. Miers withdrew, U.S. troops marked the 2,000th death in the
Iraq war and Vice President
Dick Cheney's top aide, Lewis Libby, was indicted by a federal grand jury in the investigation into who leaked a covert
CIA operative's name in 2003