Still accepting?
SkyWithFluffyclouds said
But Tom Riddle himself didn't know he was a half blood when he was sorted.
Edit: And I would think that after the war they would take steps to be more accepting as it is a delicate subject.
During a webchat in 2007, J.K. Rowling mentioned, in a response to a question about Slytherin house, "Slytherin has become diluted. It is no longer the pureblood bastion it once was."Seeing as we're halfway there I would say that muggleborns must have been trickling in, maybe not fully accepted but it would be a thing in progress.
The comment was made re: a post-Deathly Hallows Hogwarts and Slytherin, which is to say that by the time Harry Potter's son, Albus, was heading off to Hogwarts, blood purity wasn't a significant defining factor of Slytherin.
"The proportion of the wizarding population that is Muggle-born is on the rise as the pure-blood families shrink in size and number."if they kept up with only purebloods and halfs then Slytherin would cease to exist as a house.
Personality traits of students seems to be the main factors the Sorting Hat would use in deciding which house students were placed in to; ambition, cunning, cleverness all seemed to be among the most important qualities in determining which students ended up in Slytherin, more than blood-purity.
Finally, in Chapter 23 of Deathly Hallows, Scabior (the Snatcher) suggests there have indeed been muggle-born members of Slytherin, though not many.I should look that up.