It took nearly an hour for Alec Baldwin, this weekend’s host of “Saturday Night Live” and its resident impersonator of President Trump, to don a certain familiar orange wig and assume the role that has occasionally infuriated the current real-life occupant of the Oval Office. In the meantime, “S.N.L.” took plenty of satirical shots at the Trump administration, starting with the return of Melissa McCarthy as the White House press secretary, Sean Spicer.

Ms. McCarthy, who made a surprise appearance last week as an agitated Mr. Spicer in an “S.N.L.” sketch that drew wide acclaim (and apparently created some consternation in Mr. Trump’s inner circle), was back in the role, in the opening of this week’s show. As Mr. Spicer, she announced to the White House press corps that “I’m calm now,” then stopped herself from swearing because, as she explained, “That’s the old Spicey, and this is the new Spicey.”

She went on to use action figures and Barbie dolls to explain a new process of “extreme vetting”; chastised the news media for failing to report on terrorist attacks like “the Horror at Six Flags,” “the Slaughter at Fraggle Rock,” and “the Night they Drove Old Dixie Down”; and plugged some of Ivanka Trump’s merchandise, a bangle and a shoe (“These babies are real head-turners”), before introducing the new attorney general, Jeff Sessions, played by the “S.N.L.” cast member Kate McKinnon.