Senate Midterm Betting Odds: Will Republicans Flip The Senate?

Written By Evan Scrimshaw on November 1, 2022 - Last Updated on November 8, 2022
midterm election odds

After midterm election odds are settled on Nov. 8, the attention will shift to odds to be the next President in 2024. But for now, there’s never been more intrigue in the race for the U.S. Senate. Can Democrats keep control of the chamber?

Let’s break down whether the betting markets are in line with reality. With Senate control coming down to the wire, and so many seats showing value for bettors, it’s the perfect time to sign up for PredictIt and lock in this bonus offer for Election Day.

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Midterm Election Odds: US Senate Control

PartyPredictIt PriceImplied Odds
Democrats$0.35 +186
Republicans$0.70 -233

Midterm Election Odds: House And Senate Exact Outcome

OutcomePredictIt PriceImplied Odds
R House, R Senate$0.69 -223
R House, D Senate$0.29 +245
D House, D Senate$0.13 +669
D House, R Senate$0.03 +3233

Betting Market Analysis

As much fun as it would be to bury the lede, Democrats are Senate favorites right now. They might not be as overwhelmingly so as they were at points, but they’re in good shape to keep control of the Senate.

To keep control, they need to win three of Arizona, Georgia, Pennsylvania and Nevada; meanwhile; the GOP needs to win two of them (because in a 50-50 Senate, the Vice President breaks ties). Democrats have reason to be quite optimistic in Arizona and Georgia, while Republicans do in Nevada. It’s a little crude to say that the race comes down to Pennsylvania, but it does.

On the Chamber control bet, Democrats are highly unlikely to win the House at this point. There’s a path, but Democrats would need to win every 50/50 race to do that. Even if you’re a Democratic optimist in the House, the 90th-percentile outcome for them is probably 210-215 seats, not the 218 they need to retain the chamber.

Given the fact that it looks like Democrats need to nearly sweep the competitive Senate map, it’s not worth talking about these seats in the abstract. Instead, let’s go through midterm election odds seat by seat in key Senate battleground states.

Arizona Senate Seat Odds

PartyPredictIt PriceImplied Odds
Democrats$0.48 +108
Republicans$0.55 -122

This is the easiest seat of the competitive board to call – Democrats should win it, and do so fairly handily. Democrats in the state have a lead in the polls, and part of the reason the polling average is low is because the GOP have been flooding the zone with polls to try and make it look competitive.

Mark Kelly has a roughly $5M edge in ad spending until election day, and given more of his spending is from his campaign, he will get cheaper ad rates and therefore disproportionately get more ads in front of people. There’s been no big ad buy from Mitch McConnell’s Super PAC, the Senate Leadership Fund, a key indicator that the GOP do not see this as particularly competitive.

As of right now, the early vote data looks good for Democrats – they’re getting their votes out from what we can tell. The value of early voting returns in Arizona and Pennsylvania are limited – polls are more valuable indicators in those states – but it’s still good to see Democrats not having turnout or enthusiasm problems.

All in, Mark Kelly should win, and do so fairly handily. That he’s an underdog in midterm election odds right now is lunacy.

Georgia Senate Seat Odds

PartyPredictIt PriceImplied Odds
Democrats$0.42 +138
Republicans$0.61 -156

Here, the polls are a bit all over the place, but we can also be fairly certain that the GOP are in deep trouble.

Right now, Black voters make up ~30% of the early votes cast in Georgia. In 2020, that number at the end of early voting was 27.7%, and Joe Biden won. In 2021’s runoff, that number was 30%.

This year looks to be tracking for somewhere between those numbers, meaning that Raphael Warnock will need to do as well as Joe Biden with white voters to beat Herschel Walker, and a bit better to win outright.

The polls in Georgia universally agree that Warnock will do so regardless of their top line results. Right-wing InsiderAdvantage has Warnock’s white share of the vote at 35.6%, and the New York Times/Siena had him at 32% – sizeable improvements on Biden’s 29% of the vote. If Warnock gets even 30%, then there’s no way Walker can “win” by any other state’s definition, let alone win outright.

If Warnock doesn’t hit 50%+1, then a runoff will occur – but in a runoff, the GOP would be in even worse shape, because a greater share of the total votes occur in Atlanta compared to in a general election. This dynamic used to help Republicans when they were the party of white Atlanta, but now that they’re collapsing in the suburbs and exurbs, they’re trading extremely red rural votes in a runoff for moderately red suburban ones. And that’s why we know it’s going to be Warnock.

It’s just a question of when.

Nevada Senate Seat Odds

PartyPredictIt PriceImplied Odds
Democrats$0.30 +233
Republicans$0.72 -257

The polls in Nevada are functionally useless at telling you who will win and by how much, which is usually good for Democrats but is bad this year.

In Nevada, a good chunk of the vote is cast before election day – even in pre-COVID 2018, 66% of the vote was cast early. Given that, early voting data has proven to be more useful at predicting the outcome of the state than its polling. This dynamic has generally benefitted Democrats, who would beat their not very good polls in Nevada because the early vote was more predictive.

Here, Democrats have had better Nevada polls in recent times, but the early vote data is close to catastrophic for them. Not so much in terms of margin, but in terms of volume. Turnout in Nevada is tracking very low, and Democrats aren’t getting their voters out.

With Nevada, 70% of the vote comes from Clark County, the southernmost county and the home of Vegas. Another 15% comes in from Washoe (home of Reno), and the rest from rural Nevada. Democrats used to win the state when their margin in Clark exceeded their margin in the rest of the state, but now they can win Washoe narrowly, which helps.

The problem for Democrats is they aren’t getting nearly enough ballots in from Clark to make up for the expected rural drubbings, and unless that pattern reverses, they will head into Election Day in their weakest position of the Obama-Trump-Biden era for a truly competitive election.

Could some of the weakness be that Democrats have gone from voting early in 2020 to voting on the day again? Sure, and in 2018 Democrats did handily win votes cast on election day in Clark. That said, if that shift was pronounced, it seems unlikely that none of the well connected Nevada politicos and insiders would have been tipped off to the possibility, let alone likelihood.

The argument for Democratic optimism in Nevada is real, and this price is too high when Democrats have two paths left – the mail votes are arriving later than usual, or they are voting on the day. That said, the argument was to trust the early vote over the polls when the polls were bad for Democrats, and changing that just because of bad news for Democrats is wrong.

Pennsylvania Senate Seat Odds

PartyPredictIt PriceImplied Odds
Democrats$0.41 +144
Republicans$0.64 -178

In Pennsylvania, we’re flying a little bit blind, because we don’t have remotely reputable post-debate polling. It’s up in the air how much the John Fetterman debate struggles will matter – especially against Dr. Oz saying decisions on abortion should be between “women, doctors, [and] local political leaders” – but we have no polls.

The New York Times/Siena poll was mostly pre-debate and had Fetterman up 6, but that’s from a pollster that is telegraphing they’re not sure how much of their 2020 failures they’ve fixed, so who knows.

The key case for Democratic optimism remains with the fact that Oz is deeply unpopular, and no matter the pollster, his negatives are at or above 50%. The only polls showing him ahead have come from pollsters who lean right, and had Trump winning Pennsylvania in 2020, which he didn’t do.

Democrats should win this race – they’re weaker here than they are in Georgia and Arizona, but there’s still nothing that should make us think that Oz is actually capable of stitching together a winning coalition. He can get close, but it’s a lot easier to go from 42% to 46% than to get to 49% or 50%, and that’s Oz’s task.

Until there’s any evidence he can get there, Democrats are favored.

Conclusions

In reality, Democrats are favored in 50 seats, and they’ve got an out in Nevada if Pennsylvania blows up on them. This is a much better situation than they have any right to be in right now, but they’re here for a reason. The GOP nominated horrible candidates in three states, and now they’re paying the price against three Democratic incumbents who are well financed and a fourth Democrat in Pennsylvania who gets to run against Dr. Oz.

Yes, the polls have been wrong in the past, but those polling misses have mostly been in the Rust Belt – also known as not the states where the Senate majority will be decided. Democrats could lose the Senate, for sure – they’re running with the headwind of an unpopular President and high inflation. But the GOP are at risk of botching it, because of abortion bans and bad candidates.

Working through these Senate races feels impossible, so best of luck navigating midterm election odds.

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Evan Scrimshaw

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