Since SwingSeat (our Senate Forecast Model) debuted last week, I’ve gotten some questions about Arizona. Right now, the model believes that Krysten Sinema, the Democratic frontrunner, has a greater than 80 percent chance of taking Jeff Flake’s old senate seat in November. To me (and to some readers) that seems high—Arizona is still at least a light-red state, and Republicans have at least one credible candidate in the race.
So why is SwingSeat so high on Sinema’s chances? And should these numbers move our assessments of the race?
SwingSeat likes Sinema’s chances because candidates who lead by a high-single-digit margin at this point tend to win more often than they lose. My simple sanity check from April suggested that when we’re 150 days out from an election, candidates who led in a simple polling average by 5-10 points won about three quarters of the time. The sanity check is only a rough guide but we’re about 130 days out from the election now and Sinema does have a high-single-digit lead, so really might have a win probability above 50 percent.
There’s an obvious response to this argument: that Arizona is a red state and the underlying fundamentals of the race should move it towards Republicans. I think that’s a fine argument, and I’m open to integrating fundamentals into the model as I tinker with it. But I’m not convinced that a fundamentals-infused forecast would cause the Democratic edge to evaporate.
If we take a 30,000 foot view of this race, what you have is an open seat in a state that Trump won by only 4 points taking place in a year where Democrats are often ahead in the generic ballot by 6 to 8 points. The Republican front-runner, Martha McSally, is a conventionally qualified candidate but it’s still unclear whether she’ll be able to unite the disparate parts of the Arizona GOP. And Arizonans might not nominate their most electable candidate. Sherriff Joe Arpaio, arguably one of the worst candidates the GOP could nominate this cycle, is still in the race. Kelli Ward, another candidate running to McSally’s right, also looks like a riskier bet when you take a long view of the polling. But it’s worth noting that McSally and Ward have polled comparably against Sinema in the two recent public polls—with Ward slightly outperforming McSally in the Marist poll.
This view of the fundamentals may be too rosy for Democrats. Maybe the Republicans will consolidate after the primary, and maybe 2012 (when Mitt Romney won the state by 9 points) is the right baseline when Trump himself isn’t on the ballot.
But the point is that Arizona isn’t West Virginia. The fundamentals don’t point to a GOP win as clearly as they do in some of the other red states that are up this cycle. And I’m guessing (again, still tinkering with this) that if you combined fundamentals with polls, you’d still get a notable (but maybe not 4-to-1) Democratic advantage in the Grand Canyon State.
