Hard to say who got more attention at Sunday’s Democratic fundraiser in Northern California: President Obama or Lady Gaga.

The pop star — in sky-high heels, floor-length lacy black dress, towering blond bouffant adorned with a black hairpiece — created a sensation at the San Jose residence of Facebook COO Sheryl Sandberg, where 75 guests paid the maximum campaign donation of $35,800 to hear a pep talk from Obama. Gaga (who has 13 million Twitter followers — 3 million more than the president) sat front and center during his remarks; ABC reports she asked him what he could do to prevent teenage bullying.

Barry Manilow is a big Ron Paul fan..who knew? (Michael N. Todaro/Getty Images)

With no Democratic challenger to Obama, the usual A-listers — George Clooney, Steven Spielberg, Tom Hanks, Gwyneth Paltrow, Anna Wintour, Jimmy Fallon, and Alicia Keys — have already decorated (and donated big money) at fundraisers for the president.

More interesting are the celebs backing the Republicans vying for the nomination. The lineup so far:

Last week, Rick Perry landed Dean Cain — you remember: He starred in TV’s “Lois & Clark: The New Adventures of Superman.” “I like him a lot,” Cain told Fox News, calling him an “ upstanding guy who will help turn us around.”

Cindy Crawford once for Obama, now she’s a Mitt fan. (Kevin Winter/Getty Images)

• Herman Cain (no relation to Dean) got the coveted Dennis Miller nod Monday — one day after an encouraging Florida straw poll. The comedian announced on his radio show that he’s donating to the campaign, headlining an L.A. fundraiser, and he suggested a bumper sticker for the pizza millionaire: “Cain Versus Not Able.” (“I look forward to working w/ him as we continue our journey to White House!” tweeted an excited Cain.)

• Ron Paul has the most curious coalition: Vince Vaughn, Barry Manilow and Chuck Norris. Vaughn and Paul go way back: The congressman attended the 2009 premiere of “Couples Retreat”; Vaughn introduced Paul at the Liberty Political Action Conference this month. Norris, who backed Mike Huckabee in 2008, now thinks Paul is one of the few “honest” politicians in Washington. And just a week ago, Manilow jumped on the bandwagon. “I think he’s solid,” he told the Daily Caller. “I agree with just about everything he says. What can I tell you?”

• Michele Bachmann, Jon Huntsman, Newt Gingrich: No big names yet — speak now, Ted Nugent, before it’s too late.

Read the full account of Gaga’s appearance at the fundraiser here.