It’s really good business in the mainstream media to shit on the odds of Democrats winning anything while nobody ever went broke predicting that Trump will win re-election despite 60% of the country hating his guts.
In every special election so far, no matter how red the district the margins have compressed. Not all of them compressed enough to give Dems the win, but those who ignore that trend, while wonderfully cynical and glib, are being counter intuitive.