Her 2003 nomination by George W. Bush to the U.S. Court of Appeals for the District of Columbia Circuit was opposed by civil rights groups and stalled for nearly two years by Democratic senators who saw her as an extreme "conservative judicial activist.” She was eventually re-nominated and confirmed in 2005.

[citation needed] From 1987 to 1989, Brown was Deputy Secretary and General Counsel for the California Business, Transportation and Housing Agency and a University of the Pacific McGeorge School of Law Adjunct Professor from 1988 to 1989.

[4] The job included diverse duties, ranging from analysis of administration policy, court decisions, and pending legislation to advice on clemency and extradition questions.

Brown was rated "not qualified" by the State Bar of California JNE Commission for her lack of experience and tendency to inject her political views into her opinion.

[7] The opinion upheld an amendment to the California Constitution which banned discrimination against or preferential treatment for any individual or group on the basis of race, sex, color, ethnicity, or national origin in public employment, education, or contracting.

[citation needed] In another case, American Academy of Pediatrics v. Lungren (1997), Brown dissented from an opinion striking down a parental consent law for abortions.

[10] Brown was nominated by President George W. Bush to the U.S. Court of Appeals for the District of Columbia Circuit on July 25, 2003 to fill the seat vacated by Stephen F. Williams.

[13]Brown's nomination to the Court of Appeals was confirmed on June 8, 2005 by a 56–43 vote, after 14 senators stuck a deal to avoid filibustering judicial nominees except in "extraordinary circumstances".

[3] One month into Brown's tenure she was reportedly considered as one of 13 potential nominees to replace retiring Justice Sandra Day O'Connor on the United States Supreme Court.

Circuit upheld an injunction that forbade the U.S. military to transfer Shawqi Ahmad Omar, a suspected insurgent, out of U.S. custody while his habeas corpus suit was pending.

The majority in effect holds that, in the proper circumstance, a single unelected district court judge can enjoin the United States military from sharing information with an allied foreign sovereign in a war zone and may do so with the deliberate purpose of foiling the efforts of the foreign sovereign to make an arrest on its own soil, in effect secreting a fugitive to prevent his capture.

[22]In 2012, she wrote a concurring opinion for the case Hettinga v. United States in which she severely criticized the dominant post-Lochner approach in the U.S. judiciary, that laws involving economic policy deserve "a strong presumption of validity.

"[23][24] In June 2017, Brown wrote for a unanimous circuit panel finding that the next friend of Yemenis killed in a U.S. drone strike could not sue under the Torture Victims Protection Act nor the Alien Tort Statute because the attack was not justiciable.

[25][26] However she wrote a separate concurring opinion that criticized this lack of oversight, which is barred by precedent[citation needed], concluding, "The political question doctrine, and the state secrets privilege confer such deference to the Executive in the foreign relations arena that the Judiciary has no part to play.

"[27] In August 2017, Brown partially dissented when the court found that the Military Extraterritorial Jurisdiction Act authorized the prosecution of the Nisour Square massacre killers.

[31] In 2019, Brown held the position of jurist-in-residence, funded by a grant from the Hugh and Hazel Darling Foundation, at University of California Berkeley School of Law, co-teaching a workshop class with John Yoo and Steven F.

Brown's speech cited Ayn Rand and lamented the triumph of "the collectivist impulse" in which capitalism receives "contemptuous tolerance but only for its capacity to feed the insatiable maw of socialism."

Brown argued that "where government moves in, community retreats, civil society disintegrates, and our ability to control our own destiny atrophies" and suggested that the ultimate result for the United States has been a "debased, debauched culture which finds moral depravity entertaining and virtue contemptible.

In an exegesis of Brown's speech that was largely responsible for bringing it to public attention during her confirmation process in 2005, legal-affairs analyst Stuart Taylor Jr. noted, "Almost all modern constitutional scholars have rejected Lochnerism as 'the quintessence of judicial usurpation of power'" and cited "leading conservatives — including Justice Antonin Scalia, Senator Orrin Hatch, and former Attorney General Edwin Meese, as well as [Robert] Bork.