Will eventually resolve to the party which won the popular vote for the race, as determined by the local, state, and ultimately federal governments.
In the case the race is called by the major news organizations, the market may optionally resolve early.
This market covers events up to and including Election Day, November 5: if Party A's candidate X wins the popular vote that day, but intervening events cause the next inaugurated Senator to be from Party B, the market will resolve to Party A.
If candidate X switches party affiliations, the switch will not affect the outcome if it is after the beginning of Election Day, local time.
1,000
3.00Analysis from the Manifold newsletter:
Arizona: Ruben Gallego (D) vs. Kari Lake (R)
Democrat win chances per models: 84% (The Hill), 88% (538), 82% (Split Ticket)
Expert forecasts: Lean D (flip) (Cook), Lean D (flip) (Sabato), Tilt D (flip) (Inside Elections)
Polling average (538): Gallego+7
Election result in 2018, a Democratic wave year: D+2.4 (Sinema vs. McSally)
Election result in 2012, amid Obama's reelection: R+3 (Flake vs. Carmona)
Recent Arizona presidential election results: Biden+0.3 (2020), Trump+4 (2016), Romney+9 (2012)
Manifolder commentary (from “Will Kyrsten Sinema win the 2024 Senate election in Arizona?”, from almost 2 years ago)
Matt P: Sinema is way more politically savvy than people give her credit for. Just like Joe Manchin, she will be reviled by the left wing of her party, but will sit in that Senate seat until she dies or retires.
Conflux: Right. Presumably if she runs against a Democrat and a Republican, the Republican just wins. So her best chance would be to get cross-endorsed by the Democrats or something, but everyone hates her now. I guess I should be betting this even lower.
Zachary Freitas-Groff: I brought this up from 16% to 33% yesterday. Incumbents have a very strong advantage with re-election rates well north of 80%. This race is weird, yes, but I'd have thought she's more likely to win than not. And when I think of senators going independent, I think of, e.g., Joe Lieberman who won, and to a lesser extent Angus King and Lisa Murkowski. It seems like most likely it's a three-way race where the money seems close to even on any of the three parties, with a smaller chance one party chooses not to nominate someone, in which case she likely wins. Am I missing something?
BRTD: that's assuming that a non-negligible number of Democratic voters vote for the candidate with a 5% favorability rating amongst Democrats
BRTD: Time to resolve [whether Sinema runs] as NO
Conflux commentary:
This race is an inverted version of West Virginia. If the current Democrat-caucusing Independent, Kyrsten Sinema, was still in the race, it would be very different — but it’d probably hurt, not help, the Democrats’ chances.
Since Sinema has declared she’s out of the race, there’s been less interest from Manifold. Democratic Rep. Ruben Gallego is popular, and his opponent Kari Lake, an ardent election denialist who lost the 2022 gubernatorial election, is less so. In red-leaning Arizona, Gallego is running ahead of Harris by 9 percentage points in polls. It seems likely the gap will tighten, but along with the preceding races, Democrats seem to be doing better than expected.
Due to the unfortunate map, though, still probably not enough to keep the chamber.