Will RFK Jr. play spoiler at the state level? New polling says … maybe.

That’s the obvious point: the major-party candidates fear Kennedy will pull away voters they need to eke out a majority in a state. Each man won the presidency thanks to narrow margins in a handful of states, after all, so the prospect of seeing a swing state swing in the other direction because of Kennedy is particularly unappealing.

New data from Fox News’s well-respected polling arm offers insight into how real that threat is. The verdict?

The poll was conducted in Georgia, Michigan, Pennsylvania and Wisconsin, four states that flipped from backing Trump in 2016 to preferring Biden in 2020. (The Michigan results weren’t really that close last time, but whatever.) In every state except Georgia — where Trump has a stronger lead — the results in a head-to-head contest between the major-party candidates show a functionally tied race. When Kennedy is added to the mix? The results in every state except Georgia show a functionally tied race.

You can see the shifts below. On the outside of each graph are the results of the poll when Biden and Trump are the only offered options; the center three columns show the results when Kennedy is in the mix. At the top of each Biden and Trump column in the middle is the percentage-point drop the candidates experience when thrown into the larger field.

Pennsylvania and Wisconsin go from tied to one candidate having a two-point lead when the field is larger, but “a two-point lead” and “tied” are functionally the same thing when you consider margins of error. In other words, there’s no obvious effect on the outcome shown in the polls. But there would be some effect on Election Day — an uncertain one that both major-party candidates want to shape.

The Fox News poll asked about the full field before the head-to-head matchup in each state. Asking both questions allowed it to break down the head-to-head support for Trump and Biden relative to how those same respondents had answered the question about the full field.

In each state, about 9 in 10 of those who picked either Trump or Biden in the head-to-head question had also chosen that candidate when presented with the full field. But anywhere from about 5 to 10 percent of those candidates’ head-to-head support came from people who picked Kennedy when given the choice.

In Michigan, for example, 1 in 10 respondents who picked Trump in the head-to-head contest had picked Kennedy when given the fuller field. If Kennedy didn’t make the ballot in Michigan, that would be better news for the former president. Unfortunately for Trump, he did.

We can summarize these findings accurately and unsatisfactorily. Kennedy’s presence on the ballot in swing states would pull voters from both major-party candidates. The effect of doing so, however, is uncertain, and it’s not clear that Kennedy would shift the winner in any state from Trump to Biden or vice versa. But, also? He might.

For the major-party campaigns, the takeaway is simpler: Kennedy’s candidacy constitutes the worst kind of wrench in the system — one with an unclear outcome.