(CNN) – Former Solicitor General Ted Olson formally endorsed John McCain Friday, the Arizona senator's campaign announced.

"I have long admired John McCain for his courage, character, and integrity," Olson said in a statment. "He is the candidate best prepared to lead as commander in chief from day one. John McCain has a deep-rooted conservative philosophy and I trust him to appoint strict constructionists, like Chief Justice Roberts and Justices Scalia, Thomas and Alito, to judicial positions."

CNN first reported news of the endorsement Thursday night.

Olson, who had supported Rudy Giuliani's White House bid, is a well respected conservative, particularly with respect to judicial appointments. He's a member of the highly regarded Federalist Society — an organization that promotes the teaching of state's rights and a limited federal government in the nation's best law schools.

Olson also helped steer the 2000 Florida recount effort on behalf of President Bush, and served as member of the Reagan Justice Department.

The endorsement will be a welcome one for McCain, who continues to face distrust from many of his party’s most conservative quarters. Olson has connections to many of the Arizona Republican's harshest critics, and is likely able to make inroads with some of them.

– CNN's Dana Bash contributed to this report