NEW YORK » All last week, Lorne Michaels, the creator and longtime executive producer of "Saturday Night Live" was working the phone trying to nail down a visit to the show from either of this year’s presidential candidates. By late Friday, it looked like it wouldn’t happen, at least for this last week.

But Michaels still needed star power. So he put in a call to Big Bird.

Mitt Romney had mentioned the Sesame Street character while discussing his planned cuts to financing for PBS on Wednesday, so Michaels had his writers create a Big Bird segment for the show’s "Weekend Update." But executives at the Children’s Television Workshop were reluctant to have their beloved character in anything that could be construed as political commentary.

After Michaels made a personal appeal to some friends at the company and let them look at the script, they signed on Friday night. Caroll Spinney, the only actor to play Big Bird since 1969, was told to get his 8-foot yellow-feathered costume ready.

"There’s always all this swirl," Michaels said, describing the buildup to the show, "and then you’re fighting to get Big Bird on the phone."

Political season is high-anxiety season for "SNL," which even in the age of Jon Stewart and Stephen Colbert is known for its definitive parodies of political debates. That includes Phil Hartman as Bill Clinton promoting his record in Arkansas ("Just this year we passed Mississippi to become 41st in the prevention of rickets"), Dana Carvey as both George H.W. Bush and Ross Perot, and a 2000 debate between a pedantic Al Gore and an addled George W. Bush, in which each offered one-word summaries of their campaigns, "lockbox" and "strategery."

Michaels and NBC, usually very protective about the process of putting together "SNL," allowed access to the show’s writers, stars and rehearsals this week as they prepared their debate sketch. Pointing to the more than 70 million people who watched the actual debate, Michaels said, "How else can you get anything that can play as comedy where everyone has seen it?"

But the debate itself turned out to be a challenge. There were no big gaffes or obvious springboards for comedy. Instead, the first debate of this election offered up a blizzard of policy details and a lackluster performance from President Barack Obama.

At home Wednesday night, Seth Meyers, one of the show’s head writers, watched with increasing concern.

"It’s boring enough when they’re talking about all this and how it will affect Americans, but when you’re sitting there trying to pull comedy out of it, it’s really bad," Meyers said. "There were people on Twitter saying: ‘You must be really happy, there’s so much in this debate. This is writing itself.’ I was like: What debate are you watching?"

The job of turning the debate into comedy gold fell to Jim Downey, the longtime "SNL" writer who has created the show’s debate parodies since the 1970s. This one, he said, was the hardest he had ever dealt with.

"I can never remember one that didn’t have something," said Downey, who watched the debate by himself at home. "Some kind of thing that was odd or weird."Wednesday night and throughout Thursday, Michaels exchanged emails with Downey, getting the gist of his idea that Obama would be distracted by the fact that he had forgotten to buy his wife an anniversary present. Downey’s genius, Michaels said, was summed up in his 2000 sketch that featured the word "strategery."

"Bush didn’t say it, but people think he did," he said.

Michaels also watched the post-debate coverage on MSNBC where the hosts Chris Matthews and Ed Schultz reacted strongly to the president’s weak performance.

"Rachel Maddow looked like she had just seen a terrible car accident," he said.

Sensing another opportunity, he discussed it with the show’s writers, who, like Michaels, occupy a warren of offices on the eighth floor at 30 Rockefeller Center.

Downey, working mostly alone at home on his initial drafts, which he dictates by phone to his assistant, continued to ponder how to create the main debate sketch. By Friday afternoon, when the first run-through was scheduled, the script still was not complete.

"This was the toughest assignment I’ve ever had on one of these," he said later. By late Friday evening, the performers — Jay Pharaoh as Obama, and Jason Sudeikis as Mitt Romney — were able to do a partial run-through so that directors and producers could at least work on the staging.

Michaels, with a still unfinished sketch on his hands, was toying with opening the show with an MSNBC sketch, even though chronologically it would have happened after the debate. Meyers and the co-head writer Colin Jost stood in front of a run-through of the MSNBC sketch during dress rehearsal, taking notes. Before the live show, an entire character, Ed Schultz, played by Bobby Moynihan, had been cut, and a new joke for Chris Matthews about Obama needing a Mike Tyson face tattoo for the next debate had been added.

In the late afternoon, Downey was still agonizing. Worried that his initial idea about the anniversary present was not enough, he had added a voice-over in which Obama describes the effects of altitude sickness, which Gore had suggested on Current TV was responsible for Obama’s debate performance. Downey wanted to have Obama stagger through the line "must … hang … on … for Michelle," based on how Superman is typically portrayed in comic books reacting to Kryptonite.

"I have to admit it," Downey said. "It was because Al Gore suggested the altitude thing."

The cast did not receive the final version of the sketch until 6 p.m., two hours before the live audience would file in and five-and-a-half hours before millions of viewers, armed with high expectations, would tune in. As Pharaoh and Sudeikis ran through their lines, Downey, script in hand and glasses on forehead, stood on the set, closely monitoring the rehearsal and describing in detail what he wanted in the scene.

Sudeikis worked on delivering Romney’s list of 41 fixes for the economy (which included "six abrupt reversals of opinion and three lies") in a modulated tone that allowed the Obama voice-over to be prominent. That was crucial because Downey had included a moment in which the moderator, Jim Lehrer, (played by a former cast member, Chris Parnell, in a guest appearance) interrupts to ask the president if he just heard Romney take credit for killing Osama bin Laden.

"The audience couldn’t be allowed to hear that Jason hadn’t actually said that," Downey said.

But he was so unsure of the sketch at this point that he thought of cutting it completely and reassigning the bin Laden line.

"After dress, I said, ‘Maybe we should cut the piece out of the show and just take that 25-second exchange and give it to the MSNBC sketch."’

That suggestion was not taken. The sketch was trimmed during the break between the two performances, the most difficult technical details were smoothed out and it opened the show. The bin Laden line drew the biggest laugh of the sketch.

"That was probably the best moment," Downey said. "It was my favorite moment."

Midway through the live show, Downey sat in a conference room, watching on a monitor. He looked wrung out from the effort to wring comedy from the debate.

"It’s my 60th birthday today," he said. "I didn’t know if I felt like spending it in the studio under this incredible pressure."

During a commercial break, an NBC executive came over to congratulate him on the sketch. Sudeikis sat and they discussed the prospects of his playing his other recurring character, Joe Biden, in the vice-presidential debate.

That debate is set for Thursday; there is every expectation that "Saturday Night Live" will have its own version two nights later.