Rob Reiner, one of the industry’s most prominent political activists, is endorsing Wendy Greuel in her bid for the West side Los Angeles congressional seat held by Henry Waxman, in what is expected to be a competitive race among Democrats for prominent supporters and key donors.

“I have obviously been a long-time supporter of Henry Waxman, and I think she will follow in his footsteps in the same great tradition,” Reiner told Variety on Monday.

Waxman announced last month that he would not run for reelection this year, after 40 years of representing the district, which includes the liberal stronghold of the West side of Los Angeles and Santa Monica, and, following redistricting, stretches down the coast to Palos Verdes. State Sen. Ted Lieu, a Democrat who represents the Torrance area, also announced that he is running, in what could be a highly competitive intra-party race for a highly coveted congresional seat. Self-help author and lecturer Marianne Williamson and web producer Brent Roske announced their candidacies last year.

Reiner said that Lieu is “definitely a good guy,” but “I have just known Wendy for a long time. We are very much in sync on all the issues.” He said that he had already donated to her campaign, and that “whatever she asks me to do I am happy to do,” including fundraising.

Greuel, the former city controller and Los Angeles city councilwoman who waged an unsuccessful bid for mayor last year, announced that she would run shortly after Waxman announced his retirement.

She also is a former executive at Dreamworks, and Reiner said that she “certainly understands our issues,” like runaway production and intellectual property rights. But Reiner cited some of the issues he has long focused on, like early childhood education and the environment, and “she is very much in tune with that.”

“Rob Reiner has been a tireless champion on issues like universal preschool and protecting our open space, the same priorities I hold near and dear to my heart as well,” Greuel said in a statement. “Getting an endorsement like this is huge, but what makes it even better is that it comes from the director of ‘Spinal Tap.'”

Reiner said that he was “not all that surprised” that Waxman decided to retire “given the rancor that you see in Washington now, and the inability to get anything done because of such a small extreme faction that is holding the government hostage. He may feel like it is time to move on. It makes sense to me.”