Sen. JD Vance (R-Ohio), the Republican Party’s vice-presidential nominee, narrowed down his appearances on the Sunday political talk shows this weekend to just one: Fox News. Perhaps this was because his multiple appearances a week ago had him trying to defend his running mate Donald Trump’s past engagement with a notorious antisemite; perhaps it was because he is viewed broadly negatively, including faring relatively poorly among Fox News’s central audience, Republicans. Whatever the reason, the friendly environment allowed Vance to lean into claims that would have met more resistance elsewhere, like Trump’s long-standing insistence that every bad poll is (somehow)...