LUKE: I’m not gonna say you look concerned.
LORELAI: I’m not gonna talk about how good you’d look dressed like one of the guys from The Crucible.
The Crucible is a 1953 play by American playwright Arthur Miller. It is a a dramatised version of the Salem witch trials which took place in Massachusetts in 1692-93, the play serving as an allegory of the McCarthy era, when the US government accused people of subversion or treason based on a suspicion of communist sympathies. It won the Tony Award for Best Play in 1953, and has gone on to become a classic of American drama.
The Crucible was adapted into a film in 1996, with Arthur Miller writing the screenplay. Lorelai could easily have seen the film when it came out, if she had never seen it on stage. The Puritan clothing worn by characters in The Crucible remind Lorelai of Thanksgiving Pilgrim costumes.