One of Senate Minority Leader Mitch McConnell’s online ads attacking Democratic opponent Alison Grimes featured her picture lined up next to President Obama, Woody Allen and Barbra Streisand.

Get it? Unpopular president + scandalized filmmaker + Hollywood liberal elite.

Such guilt-by-association tactics are typical for Republican campaigns aiming to take advantage of Hollywood support for Democratic opponents. But this year it also underscores showbiz interest in a race that is one of the few opportunities for a Democratic gain in the Senate in a landscape where the party is otherwise playing defense. Fundraisers are trying to instill a sense of urgency among donors on the very real prospect of Democrats losing the Senate majority, and to contribute even if that means setting aside significant policy differences.

“It is enormously challenging,” says producer-manager Keith Addis of the fundraising environment. “But there is a growing level of interest among Democratic players of the serious chances of losing the Democratic majority.” Addis recently hosted Sen. Mark Begich (D-Alaska) at his home for a fundraiser and has been raising for other candidates.

Interest will only increase after Labor Day, when just about any candidate facing a serious challenge is expected to make a final trek to L.A. donor circles. Among the candidates scheduled are Michelle Nunn, seeking one of the few chances of a Democratic pickup of a Senate seat, in Georgia. She is scheduled for a Sept. 9 fundraiser at the home of Michael Kong and Stacy Twilley, with tickets starting at $500.

Losing the Senate “has been a concern for a year,” says Lara Bergthold, principal and partner at campaign and communications firm Rally. “If anything, people are waking up to the idea that it is a real race and possible not to lose. They are shaking off their depression.”

The prospect of full Republican control of Congress also is reflected in the numbers coming from entertainment donors. Democratic House and Senate candidates are still garnering a majority of the contributions from showbiz sources, but the split is 65% to 34%, less lopsided than it was in 2010, according to the Center for Responsive Politics. The slight shift toward parity reflects the tendency of corporate-level donors to hedge their bets and give to both parties. House Speaker John Boehner (R-Ohio) is among the top recipients of showbiz money this cycle, according to CRP.

Grimes (pictured) has collected more from entertainment sources than any other candidate this cycle, $668,299 through the end of June, according to the CRP. She has been helped by Jeffrey Katzenberg, who took an early interest in the race last year and the prospect of defeating the Republican Senate leader, and has hosted several events for her. A who’s who of entertainment donors have given to her campaign, including James Cameron, Cameron Diaz, Ben Affleck, J.J. Abrams and Steven Spielberg.

Grimes and other candidates running in red states have not shown much reticence about raising money from Hollywood, even if it means well-worn attacks from their opponents for mingling with out-out-state elites. Rather, some Democratic incumbents have come to Los Angeles and faced crowds with significant policy differences, on such issues as gun control and the environment.

When Sen. Mark Pryor (D-Ark.) and Begich voted last year on a procedural move that sidelined gun background check legislation, some industry figures predicted a Hollywood backlash.

Some donors have withheld their support, but Pryor and Begich hardly have been shunned. Alan and Cindy Horn hosted both candidates for a fundraiser at their home in March. Addis said that singer Carole King, a longtime supporter of Democrats, called Begich “out of the blue” and offered to work for his re-election. She performed at the recent fundraiser at Addis’ home.

“Donors always have disagreements with the candidates they support and contribute to, and sometimes those disagreements loom large and sometimes less so,” says Andy Spahn, political and philanthropic consultant to Katzenberg, Spielberg and others. “Now it is less so.”

Streisand, who called for significant congressional action on gun control after the Sandy Hook shootings in December 2012, gave to Begich in late December, while Pryor has collected contributions from Katzenberg, Clarence Avant, Universal’s Jeff Shell and Dish Network’s Charlie Ergen.

Addis says that he and other donors have had long conversations with Begich over his stances on some issues, but “the bottom line is Mark Begich can’t always vote the way Southern California progressive Democrats wish he would. A progressive Democrat, who holds all the positions I do, can’t get elected in Alaska.”

He says that he has also tried to interest donors by pointing to the prospect of as many as three Supreme Court openings in the coming years, and the chance that a Democratic Senate could approve progressives to the bench if President Obama’s successor is a Democrat.

“That argument has grabbed people in a visceral and emotional way,” he says.

It’s always difficult to draw donor interest to midterm campaigns, but the challenge may be even greater this cycle. Some donors say they are still exhausted after the record-setting pace of fundraising in 2012, or they are instead looking forward to 2016 and a potential Hillary Clinton presidential candidacy. President Obama has trekked to Los Angeles three times to raise money for midterm candidates, and despite low approval numbers that may ultimately prove to be a drag on campaigns come November, a $1,000-per-person event in July at the home of “Scandal” creator Shonda Rhimes reached maximum capacity.

Here are the candidates in competitive races who have garnered the most Hollywood support, according to CRP:

Alison Grimes. Katzenberg and Harvey Weinstein recently hosted a fundraiser in New York for Grimes, helping her beat Kentucky fundraising records and nearly match the $11.8 million so far raised by McConnell. An increasing flurry of spending is expected from outside groups on both sides come fall.

McConnell, meanwhile, has seized on Grimes’ out of state donors, and at an event last month against referred to her industry support, saying that they “make fun of us at cocktail parties.”

There’s a question as to whether such attacks work. The celebrities, for instance, have since been removed from McConnell’s spots, and now just feature her, Obama and Senate Majority Leader Harry Reid (D-Nev.).

“I don’t think it is in and of itself (damaging), but they are using is as part of a message that she’s not really a part of Kentucky,” Jennifer Duffy of Cook Political Report.

McConnell, meanwhile, has collected industry contributions from DirecTV CEO Mike White and media mogul Jerry Perenchio.

Al Franken. While Franken has been low key when it comes to using his stardom to appear on national media, he has not been shy to raise money from the entertainment industry. Jon Hamm and Amy Poehler have hosted fundraisers for the senator from Minnesota, who has amassed a sizable war chest in anticipation of a tight race for re-election, including about $232,000 from entertainment sources. He’s also capitalized on the creative community’s concerns over such things as net neutrality and the pending merger of Comcast with Time Warner Cable. While he doesn’t appear to be in trouble, he’s undoubtedly aware of the 225-vote margin of victory that first got him into office in 2009.

Mark Pryor. Pryor holds one of the most vulnerable seats, with a Republican opponent Tom Cotton holding a slight lead in Arkansas. With $229,050 in contributions from showbiz, including figures such as Ted Danson and Mary Steenburgen, he has nevertheless impressed donors that his campaign is not a lost cause.

Mark Udall. Rob Reiner, Ed Zwick, Alan Horn, Spielberg and Streisand are among those who have contributed to Udall, who has collected $170,332 from the industry. Udall raised money earlier this month at Bouchon Bistro in Beverly Hills, with Clarity Partners’ Barry Porter, attorney Tom Hoberman and Dr. Howie Mandel (not to be confused with the comedian with the same name) among the co-hosts. The invite to the event quoted from an AP story on the race noting that Udall had “a tougher battle than he expected and Republicans a new pickup opportunity in their drive to win the chamber’s majority.”

Mark Begich. The Alaska senator recently attended a fundraiser at the home of Addis, raising about $100,000, a sum that can go a long way in the state’s media market. He also raised early from entertainment, drawing contributions from WGA West president Chris Keyser, producer Steve Bing and J.J. Abrams in March 2013. According to CRP, he has raised $170,332 from entertainment sources by the end of June.