I think David Valadao had a 7 point lead in his 2018 race.
I worded my question weird, sorry
I mean this:
Let’s say networks call x as winner over y prematurely
What’s the largest margin a y has ever gone on to eventually win by?
Cori Bush I think beat Lacy Clay by a rather comfortable margin.
I think you're misunderstanding the question.
It's probably NH SEN 1996.
1996 was a year where polls had Clinton up by much more than the eventual margin and the exit polls supported that idea. The networks were making calls for a Clinton +15 year when it turned out be Clinton +8, leading to a lot of questionable early calls and a few wrong ones.
