In hindsight, “take” was not the right word. But the point was that when you have a close election in a swing state, third-party candidates often get accused of robbing one of the two major candidates of that state.
There are a few problems with that claim, though. The first and most obvious one is that it (the state in question) never “belonged” to any candidate in the first place. Secondly, it assumes that the people who voted for that third-party candidate would have simply voted for someone else — presumably the Democratic or Republican candidate — if that third-party candidate wasn’t on the ballot. There were some Clinton supporters who tried to make that exact argument when Clinton lost PA, saying that Stein voters cost Clinton the state. But as Nate Silver pointed out, if we’re going by the data (exit polls, etc.), a good number of Stein voters probably wouldn’t have bothered to vote at all if Stein herself wasn’t on the ballot. And if that’s the case, it’s highly unlikely that Clinton would have won PA even if Stein had sat on the sidelines.