Rep. Henry Waxman (D-Calif.) is retiring from Congress after 40 years, a departure that means the loss of a liberal voice from a Los Angeles district heavy in entertainment industry progressives and setting up what could be a very competitive battle to succeed him.

Two independents — Marianne Williamson, spiritual teacher and self-help author; and Brent Roske, a producer — have already been campaigning for his seat, arguing that it was time for a change. But his announcement is expected to draw an expanded field of contenders, and businessman Bill Bloomfield, an independent who spent $8 million challenging Waxman in 2012, also may run.

In a statement on Thursday, Waxman seemed to agree. “The reason for my decision is simple,” he said. “After 40 years in Congress, it’s time for someone else to have the chance to make his or her mark, ideally someone who is young enough to make the long-term commitment that’s required for real legislative success.”

The race to succeed Waxman could open up a crowded field of Democratic candidates, given that the seat is heavy in progressive donors in a high-profile district and the prospect of winning a safe seat for future elections. Political consultants already were speculating on who would enter the race to succeed Waxman, with names such as former Santa Monica Mayor Bobby Shriver, already running for Los Angeles County supervisor, and Los Angeles City Councilman Bob Blumenfield being floated. Also mentioned: California Assemblyman Richard Bloom and State Sen. Ted Lieu.

Waxman was the ranking member of the House Energy and Commerce Committee, which oversees an array of media-specific issues, as well as the Internet and telecommunications. He led the committee during two years of Democratic control from 2009 to 2011. But to those in his district, which includes Beverly Hills, Malibu, Santa Monica and stretches down the coast to Rancho Palos Verdes, he was better known as the champion of issues they have long favored, including climate change legislation, environmental regulations, healthcare reform and consumer protection.

According to the Center for Responsive Politics, since 1989, entertainment sources have provided the second greatest share of Waxman’s campaign contributions, after health professionals.

Elected in the wave of Democrats who came into office following Watergate, Waxman gained a reputation as a relentless advocate for such issues, which seemed to gel with the make up of his district. It wasn’t until 2012, after California adopted an open primary, that he faced a serious challenge. Waxman won handily against Bloomfield, but with a narrower 54% of the vote, in part due to a redrawn district.

His challengers this year seemed eager to cast him in the same way that a longtime friend and colleague, Howard Berman, was characterized last year when he was unseated in his San Fernando Valley seat against Brad Sherman. While powerful figure in Congress, Berman nevertheless had to scramble to connect to voters in a newly drawn district.

On showbiz issues, Waxman could be an ally, but with limits. He was a supporter of legislation to establish a performance right for musicians, and backed measures to curb illegal file-sharing. But he was also relentless in probing the broadcast networks’ flubbed call of winners in the 2000 presidential race. The congressman tried repeatedly — and ultimately unsuccessfully — to get NBC to hand over a videotape allegedly of then-head of GE Jack Welch pressing the news staff to declare George W. Bush the winner. He also made an unsuccessful effort in 2010 to come up with net neutrality legislation, an issue in which Hollywood studios were ambiguous but many Internet service providers opposed.

MPAA chairman Chris Dodd, who served in Congress from 1975 to 2011, noted that he and Waxman were elected in the same year. “I saw what a tireless advocate he was not only for the people of Southern California. but for consumers all across the country,” Dodd said in a statement.

The departure of Waxman, along with the exit of Berman last year, is viewed by some in the industry lobby as a loss of influential voices for various issues, but also a blow to the Los Angeles region in terms of congressional seniority and leadership.

“I have had a long career and an eventful one – and I wouldn’t trade any of it,” Waxman said in a statement.  “I woke each day looking forward to opportunities to make our country stronger, healthier, and fairer.  And I will always be grateful for this honor and privilege.”

Update: Sandra Fluke, who was denied a chance to testify on Obamacare and contraception, and later became an instant celebrity in the furor Rush Limbaugh used the words “slut’ and “prostitute” to describe her, told KPCC that she is considering a bid.

Second Update: Wendy Greuel, former city controller and Dreamworks executive, said that she is running for the seat. “I am going to fight like Congressman Henry Waxman on issues important to our families,” she said via Twitter. She will have an advantage in name recognition and a donor network she built in her unsuccessful run for mayor of Los Angeles.