[4] At Notre Dame, Manion was a three-time champion in the Bengal Bouts, a boxing tournament begun by legendary football coach Knute Rockne.

[2] On February 21, 1986, President Ronald Reagan nominated Manion to the United States Court of Appeals for the Seventh Circuit, to a seat vacated by Judge Wilbur Frank Pell Jr.

In a radio address to the nation, President Reagan stated, "I know [Daniel Manion] to be a person who has the ability and determination to become the kind of judge the American people want in the federal courts; one who believes in the rule of law, who reveres the Constitution, and whose sense of fairness and justice is above reproach.

Criticism of him as a nominee came for spelling and grammatical errors in legal briefs submitted to the Senate Judiciary Committee and for his support for the John Birch Society.

[7] The nomination was controversial;[4] Manion was confirmed 48–46 on June 26, 1986 and reaffirmed 50–49 on July 23, 1986 with Vice President George Bush casting a tie-breaking vote.

In 1986, one month after his brother's judicial confirmation, he was mentioned in an FBI investigation[12] regarding a purported release of classified information to Chilean officials "about a covert American intelligence-gathering operation".