Tim Robbins, Susan Sarandon and Sean Penn protest the war. Leonardo DiCaprio has taken on global warming and Mike Farrell stands vigil against the death penalty.
But when it comes to immigration reform - a controversy in Hollywood's own back yard - stars have largely been unseen and unheard.
Fear of career damage, confusion over a complex issue abruptly supercharged by waves of nationwide protests, and historic detachment from Latino realities are among the explanations offered by industry insiders and observers.
Not that the movement has needed famous standard bearers - it has been notable for its bottom-up genesis that has left it without recognizable leaders.
Still, there are no good excuses for the celebrity vacuum, Latino rights groups contend.
"I remember the civil rights struggle, when we had people like Harry Belafonte coming forth and being at the head and knowing the subject matter really well," said Alex Nogales, president of the National Hispanic Media Coalition. "We're missing that here."
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Do famous Latinos have a moral obligation to get involved?
"Of course," Nogales said. "This is part and parcel of being a Latino and having the responsibility to safeguard our community. The more visible ones have to take a stand. They can't always be safe."
There have been only scattered celebrity sightings at marches, with Academy Award-nominated actor Edward James Olmos (the new HBO movie "Walkout," "Stand and Deliver") the best-known.
A few other prominent Latinos, including actor-comedian George Lopez and filmmaker Gregory Nava, candidly address the public debate and the role they will - or won't - play.
"I agree with them in saying we should get involved," Lopez told the Associated Press, referring to Latino advocates. "I think the thing that frightens Hollywood right now is it's such a powder keg, they're afraid of getting burned, as public figures."
For Olmos, his involvement represents yet another chapter in a lifetime of activism. He considers the immigration issue central to the crucial debate over humane economic treatment of people worldwide.
"I think it's important because of the complexity of the issues that are involved," he said. "I wish there was a simple answer to this, but I think both sides have to come to terms with the realities of what we're facing."
Sarandon, Ed Begley Jr. and Ed Asner, all known for their political outspokenness, were contacted for interviews but either were unavailable (in Sarandon's case) or did not return phone calls or e-mail requests.
There are risks in speaking out politically, acknowledged former "MASH" TV star Farrell, and that may preoccupy some celebrities with a history of activism.
"There are some people who have been battered and beaten as a result of their opposition to the war," he said, "that I think they are a little less willing to stick their heads out from their shells."