Dreyfus has been winning over and over again for playing Selina Meyer on HBO's "Veep".
The actress played presidential candidate Hillary Clinton during the most recent season, and thanked Clinton during her acceptance speech.
Not only did Louis-Dreyfus beat out "Mom" actress Allison Janney, who has two lead actress Emmys of her own, but she also edged out "Black-ish" actress Tracee Ellis Ross and Jane Fonda (Netflix's "Grace and Frankie").
"We had a storyline about an impeachment but we abandoned that because we were anxious someone else might get to it first", she said with a not-so-subtle jab at President Trump.
Waithe became the first Black woman to ever win the Emmy for that category.
First-time Emmy host Stephen Colbert kicked off the show with an interesting surprise, bringing former White House Press Secretary Sean Spicer on stage.More news: Motherhood has become less appealing with age, says Jennifer Lawrence
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She teared up as she gave her thanks Sunday night. He won twice for lead actor in a comedy for his work in "30 Rock". Louis-Dreyfus submitted the season six finale, "Groundbreaking", for Emmy consideration this year.
"He's the reason I am probably up here", Glover said.
A victory by NBC's "This Is Us", the first network drama series to be nominated since CBS' "The Good Wife" in 2011.
"It is filled with shame and secrecy, and by you acknowledging me with this award, it shines a light on it even more", she said.
Julia Louis-Dreyfus had a lot of competition in the category.
Writing, Limited Series, Movie or Special: Charlie Brooker, "Black Mirror: San Junipero". "Both in person and around the world", Spicer shouted with authority, echoing his claim that Trump's inauguration crowd was the biggest ever and evoking McCarthy's manic portrayal of him.
Colbert thanked the president for tuning in Sunday, joking that Trump is the only one who has enough time to keep current on all that's going on in television nowadays.