Martin Leach-Cross Feldman

Feldman was among seventy-one Jewish delegates (prior to his conversion to Roman Catholicism) and alternates to the convention.[2][5]

In 1974, Feldman lost a race, 67–32, in the Republican State Central Committee to John H. Cade Jr., for selection as Louisiana Republican National Committeeman.[6]

Feldman considered himself a "traditional" or "old-fashioned" conservative. However, in December 2017, he denounced Roy Moore as a "right-wing nut". He was known to err on the side of limited government. When speaking of the Constitution, Feldman once remarked "It says what it says".[7]

Feldman was nominated by President Ronald Reagan on September 9, 1983, to a seat on the United States District Court for the Eastern District of Louisiana vacated by Judge Jack Murphy Gordon. He was confirmed by the United States Senate on October 4, 1983, and received his commission the following day.[4][3] In addition to his service on the District Court in New Orleans, Feldman served a term on the FISA Court from 2010 to 2017.[8]

On September 3, 2014, Feldman issued a ruling upholding Louisiana's ban of same-sex marriage. After the United States Supreme Court ruled Section 3 of the Defense of Marriage Act, the federal statute that banned the United States federal government from recognizing same-sex marriage, as unconstitutional in United States v. Windsor, he was the only district federal judge to uphold a state prohibition against same-sex marriage. Feldman said that the state has a legitimate interest in upholding the state's 2004 amendment to the state constitution defining marriage as between one man and one woman that was approved by 78% of voters. Feldman stated, "marriage is a legitimate concern of state law and policy, and that it may be rightly regulated because of what for centuries has been its role."

Feldman also equated the recognition of marriage without regard to sex to incest, writing that he was concerned that recognizing marriage without regard to the sex of the members of the couple would lead to a slippery slope that would eventually require courts to recognize polygamy and incest.[9]

For example, must the states permit or recognize a marriage between an aunt and niece? Aunt and nephew? Brother/brother? Father and child? May minors marry? Must marriage be limited to only two people? What about a transgender spouse? Is such a union same-gender or male-female? All such unions would undeniably be equally committed to love and caring for one another, just like the plaintiffs.

— Judge Feldman, Robicheaux v. Caldwell ruling

Lawyers for the plaintiffs immediately announced plans to appeal the ruling.

In January 2015, the case was heard in the U.S. Court of Appeals for the Fifth Circuit, alongside cases from Texas and Mississippi. The decision remained unresolved at the time of the June 26 Obergefell decision. Following the Supreme Court decision, the appeals court remanded the case back down to Feldman and the district court for a reversal of order ruling in favor of the Louisiana plaintiffs.

On June 22, 2010, Feldman issued a preliminary injunction blocking a six-month moratorium on deep-water offshore drilling in Hornbeck Offshore Services LLC v. Salazar. White House press secretary Robert Gibbs indicated that the Obama administration intended to immediately appeal the decision to the Fifth Circuit Court of Appeals.[10]

Feldman's 2008 financial disclosure report[11] indicates that in that year, he owned stock in Transocean (worth under $15,000), the company that owned the Deepwater Horizon rig, as well as in other oil companies which would be affected by the moratorium.[12] A federal judge is required to consider recusal when he owns shares in one of the parties in the case before him, however none of the companies listed in Feldman's 2008 disclosure were directly involved in the action against Salazar.

Feldman's 2009 financial disclosure report[13] indicates that he had financial investments in multiple BlackRock funds, each valued under $15000, much like the prior year. Although Blackrock was said to be the largest holder of BP stock, it's not clear that any of these funds held stock in BP. Feldman held stock in Exxon-Mobil during the hearing on the drilling moratorium and from June 8 to 21, he issued several orders related to the moratorium case. On June 22, at the "opening of the stock market", he reportedly sold his Exxon-Mobil stock. Hours later, he issued his ruling lifting the moratorium.[14]

As of the June 9, 2010 amended complaint, Transocean, Black Rock, BP, and Exxon-Mobil were not plaintiffs in the action.[15]

On August 17, 2020, Feldman ruled that Louisiana's bar closures due to the COVID-19 pandemic are constitutional.[16]