Celebrities on the right are largely staying on the sidelines in the 2012 presidential race, while liberals in Hollywood are lining up behind President Obama’s reelection bid.

In many ways, the conventional wisdom of the left being disappointed with Obama and the right fired up to beat him does not apply to the stars who regularly walk the red carpet.

While liberals across the country have expressed frustration with Obama — HBO host Bill Maher called him “a moderate Republican” — the president’s base in Tinseltown is on board.

{mosads}George Clooney, Julia Roberts, Tom Hanks, Gwyneth Paltrow, producer Harvey Weistein and many others in the film industry have already endorsed Obama. Some, such as Scarlett Johansson, have acknowledged they were disappointed somewhat by Obama’s first term while adding they want him to win next year.

Meanwhile, only a few bold-faced names on the GOP side have picked their favorites in the Republican presidential primary.

Clint Eastwood praised Herman Cain, though he stopped short of endorsing the former Godfather’s Pizza CEO.

Actor Kelsey Grammer endorsed Rudy Giuliani in the 2008 primary race and campaigned for Sen. John McCain (R-Ariz.) in the general election. But the “Frasier” star has not endorsed this time around, despite reports he’s backing Rep. Michele Bachmann (R-Minn.).

Grammer and Bachmann both appeared in a “Troopathon” fundraiser in June, which led to the reports. But they’re not true, says Grammer’s spokesman, who told The Hill the actor “has not endorsed any candidate.”

Bachmann has attracted several celebrity backers, including Wayne Newton.

The singer, a friend of Senate Majority Leader Harry Reid’s (D-Nev.), endorsed her after a Republican presidential debate in Las Vegas. He gave her a hug and a kiss during an interview on Fox News, saying, “I will support this beautiful lady as long as she wants to go.”

Ben Stein, known in part for his “Bueller … Bueller … Bueller” line in the 1986 film “Ferris Bueller’s Day Off,” donated to Bachmann’s campaign earlier year. Best-selling author Dean Koontz also cut a check for the outspoken conservative legislator.

Actor Gary Sinise, who endorsed McCain in 2008, has no plans to back a candidate this time around. “Gary isn’t registered with any political party, and isn’t endorsing a candidate,” a spokeswoman for Sinise said.

Jon Cryer, the “Two And A Half Men” actor who endorsed McCain three years ago, is also not going public with his candidate of choice.

“Jon is not a Republican. The mistake was made because in 2008 he attended events for both parties. It seems the Republican Party was very quick to align him with their group of supporters. He did attend events for both parties, because he wanted to hear what both sides had to say. He’s not really political,” said Cryer’s spokeswoman, Karen Sanfilippo.

Endorsements can be a touchy topic. Singer Barry Manilow caused a stir when he said in September that he agrees with “just about everything” Rep. Ron Paul (R-Texas) says.

However, Manilow, who contributed to Paul and Democratic presidential candidates in 2008, will be voting for Obama next year, his representative subsequently said.

Vince Vaughn has not walked back his comments on Paul. He introduced the Texas lawmaker at the Liberty Political Action Conference in Reno, Nev., in September. “I was just impressed with his talking points” on the Federal Reserve, the actor said in his introduction. “His philosophies are consistent; they do not waver based on polls or public opinion.”

Some conservatives have been outspoken in their support of Rick Perry.

Actors Stephen Baldwin, Dean Cain and Janine Turner — along with Kiss’s Gene Simmons and singer Pat Boone — are all supporting the Texas governor.

“He will be our next president,” Simmons tweeted of Perry in August. “I’ve never been wrong.”

Russell Crowe is a longtime friend of Perry’s but hasn’t said whether he’ll endorse the Texas governor for president.

This cycle contrasts sharply with 2008, when celebrities endorsed early and often during the Republican primary. Political observers in California cite a variety of reasons: a divisive political climate, the choices in the Republican field, a lack of conservative star power.

Trevor Neilson, co-founder and partner at Global Philanthropy Group, which advises high-profile clients on philanthropic strategy, said,  “There are not as many influential people who are conservatives who are on the West Coast. There are plenty of conservatives out here, but if you look at leaders in media, technology and entertainment, which are three of the big industries, they tend to be progressive.”

But some on the right, including lightning rod Andrew Breitbart, have said there are many Republicans in Hollywood. Yet they fear going public because it will affect their careers in the left-leaning town.

Adam Mendelsohn, a former deputy chief of staff for California Gov. Arnold Schwarzenegger (R) who is now at Mercury Public Affairs, blames a “hostile” political environment.

“The country is very fractured. There’s a lot of frustration,” he said. “Whereas before celebrities could get involved in politics and not risk alienating themselves from vast consumers and audiences, it is a different environment right now, and maybe some of the celebrities are asking themselves if they want to risk the blowback that goes with getting involved in such a highly charged election.

“It was less risky to get involved in previous elections than it is now.”

Mitt Romney, a front-runner for the nomination, has not collected a lot of celebrity support for his 2012 bid.

{mossecondads}Actress and model Cindy Crawford, who backed Obama in 2008, appeared at a Romney fundraising event in May, triggering a lot of chatter on the Internet.

Publicist Annett Wolf explained at the time that Crawford attended the event as a favor to Tagg Romney, who is a friend of Crawford’s and the son of the ex-Massachusetts governor. Wolf added that like many other people, Crawford is undecided on whom she will support in 2012.

Clearly, Republicans who want to defeat Obama are focused on GOP voters in Iowa, New Hampshire and other early primary states. While the eventual Republican nominee might court celebrities during the general election, Obama is not waiting.

He’s made two trips to the West Coast over the past couple of months, appearing at fundraisers with actors Will Smith and Eva Longoria, among others.

That kind of star power can have a downside, however. In tough economic times, Obama and others running for the White House risk looking out of touch with average voters when they are rubbing elbows with movie stars.

But Neilson, who attended an October fundraiser for Obama hosted by Melanie Griffith and Antonio Banderas, says the president can benefit from his time with celebrities.

“As long as he does [celebrity fundraisers] with the right people it’s a net positive for him,” Neilson said, noting that he means “people who are seen as being serious about their philanthropy, people who are seen as being serious about engaging in the issues that impact the country.”

Others say celebrity endorsements are not what they used to be.

Mendelsohn said, “We live in a culture that is completely oversaturated with celebrities — reality TV, blogs, websites and TMZ — and I think that a lot of the allure of the celebrity doesn’t have the impact it had.”

— Peter Sullivan contributed to this report.