It takes seven minutes.
A dusting of Clinique Stay-Matte powder in honey. A hand-stitched wig. Eyebrows glued up into tiny peaks. The rest is left to Alec Baldwin: the puckered lips, a studied lumbering gait and a wariness of humanizing a man he reviles.
The transformation of Mr. Baldwin, an outspoken liberal, into the president-elect, Donald J. Trump, for his running parody on NBC’s “Saturday Night Live,” entails a tangerine hairpiece and a tricky tightrope walk. It means balancing a veteran actor’s determination to merge his identity into a character, even as, in his offstage life, he is firm in his belief that the man about to take office is a dangerous figure.
The key to a convincing Mr. Trump, the actor said, are “puffs” — his word for the pregnant pauses in the president-elect’s speech. “I see a guy who seems to pause and dig for the more precise and better language he wants to use, and never finds it,” Mr. Baldwin said in an interview on Saturday in his dressing room at 30 Rockefeller Plaza in Manhattan, six hours before show time, his eyebrows already peaked. “It’s the same dish — it’s a grilled-cheese sandwich rhetorically over and over again.”
Much has been made of Mr. Trump’s hands. For Mr. Baldwin, they are a focus, but for their movements. Before the actor’s first appearance, he watched hours of rallies and campaign appearances to mimic Mr. Trump’s style.
His Trump is as much censure as impersonation. He does not write the sketches. He is paid $1,400 for each appearance on the show, he said.
“I’m not interested much by what’s inside him,” he said, but in how he moves and takes up space. Mr. Baldwin then amplifies the gestures, and distills them. An emphatic wave becomes a goofy “wax-on, wax-off” movement, he said, the simple hand motion reducing a candidate to an essence: pitchman.
“Saturday Night Live” happens at a lightning pace: Those minutes of preparation include dusting the sunset color across Mr. Baldwin’s face — but not around his eyes, where “raccoon” circles of white are drawn, he said.
The wig, which on Saturday night rested high on a shelf next to the actor Kate McKinnon’s Hillary Clinton hair, is custom made for Mr. Baldwin’s head, via seven vectors measured forehead to nape, according to Jodi Mancuso, the show’s hair designer.
It helps him transform instantly,” Ms. Mancuso said. “The minute it goes on with the makeup, it’s like, ‘Oh, I get it.’”
Playing Mr. Trump as a buffoon landing headfirst in his own gaffes has at points rendered him almost sweetly silly on screen. After the election, Mr. Baldwin recalled, he was distressed to receive an email from a friend sardonically thanking him for humanizing Mr. Trump and helping him win.
“I do recognize that that is a possibility,” Mr. Baldwin said. “But I think that now that he is the president, we have an obligation — as we would if it was him or her — to dial it up as much as we can.”
As a result of his widely viewed appearances, his daily life has become a Ping-Pong match between Trump supporters’ revulsion and Trump haters’ adulation: Fans accost him on the street, some in tears. (On Sunday afternoon, while walking his dogs in Washington Square Park and talking on the phone with a reporter, Mr. Baldwin had a fan interrupt his call to bellow: “We will survive this thing!”)
Mr. Baldwin said that he planned to continue playing Mr. Trump on “Saturday Night Live” and perhaps elsewhere, but that his work schedule — he is about to film two movies — would mean his performances would be intermittent. Besides, he said, it might start to get old for audiences.
It has been suggested that Mr. Baldwin, 58, is uniquely able to portray Mr. Trump — and to rankle him — because of their similarities. In 2011, Mr. Baldwin mulled running for mayor of New York City. They can both appear thin-skinned. Antagonized by paparazzi and feeling harassed by what he says are false accusations that he uttered slurs, Mr. Baldwin has at times publicly denounced the media. On Twitter, he can be pugilistic, notably with Mr. Trump and with his brother Billy Baldwin, over their divergent political views.
Such a comparison profoundly pains Mr. Baldwin, whose father was a public-school teacher from Massapequa, on Long Island. He says he has striven not to let his financial success mar his values, and he vehemently denies the racist and homophobic slurs that have been ascribed to him. “The difference is, with Trump, it’s incontrovertible that he has said the things he’s said,” Mr. Baldwin said. “And he ran on them.’’
As a candidate, Mr. Trump protested the “Saturday Night Live” portrayal of him, calling it part of a “rigged” media campaign to undermine him. Mr. Baldwin said that Lorne Michaels, the creator and executive producer of “Saturday Night Live,” has countered that the sketch show has long been an equal-opportunity heckler.
Mr. Baldwin’s first appearance as Mr. Trump on the show was on Oct. 1, a little over a month before the election. He riffed on Mr. Trump’s irascibility and his pronunciation of “China.” Mr. Baldwin reprised the role four more times before the election, with each appearance building toward what many thought was the inevitable.
Mr. Trump’s win caught the show off guard, Mr. Baldwin said, countering expectations on the show’s set of four years of Ms. McKinnon playing her mildly maniacal Ms. Clinton as president. He also did not imagine that Mr. Trump would keep providing material. A skit on Dec. 3, depicting Mr. Trump as receiving a security briefing, hinged on the president-elect sharing a Twitter post by a 16-year-old from California. (“He really did do this,” Ms. McKinnon, playing Mr. Trump’s adviser, Kellyanne Conway, says to the camera.)
As president-elect, Mr. Trump has continued to tweet his displeasure. “Just tried watching Saturday Night Live — unwatchable! Totally biased, not funny and the Baldwin impersonation just can’t get any worse. Sad,” he posted just after midnight on Dec. 4.
Mr. Baldwin said that he considered the reprobation “funny,” even as a fake news article has circulated since his first appearance as Mr. Trump, mourning the actor’s death.
As the call to dress for rehearsal sounded in the eighth-floor corridor at 30 Rock, Mr. Baldwin ducked into his dressing room with his wife, Hilaria, and 3-year-old daughter Carmen, who had stopped by to kiss him good night, shutting the door.
Suddenly, he popped it back open.
“Whoever it is, wouldn’t it be great to be the person who pulls the sword out of the stone? Who gets rid of this guy?” Mr. Baldwin said into the hallway. “Wouldn’t that be thrilling?”
He closed the door and put on his suit.