US Midterm Election Odds 2026: Betting Points To Split Congress

The biggest day of the US Election calendar took place in the first week of November, with various governor and mayoral races across the country, in addition to a wide range of state races and referenda. 

The results were overwhelmingly favourable to the Democrats, prompting changes across political betting sites for all the major future elections.

In itself, that is no surprise. For many decades now, the party which doesn’t hold the White House has fared well in mid-term elections. 

The Democrats have been overperforming in special elections ever since Donald Trump won a second term. 

Nevertheless, their winning margins in the Virginia and New Jersey Governor races were considerably bigger than had been estimated by polls and under/over lines on betting sites.

The year 2026 will be a huge one for betting on US politics. On the first Tuesday in November, all 435 Congressional districts will hold elections for the US House of Representatives. 

Thirty-five of the 100 seats in the US Senate will be contested, along with various governorships and mayoral races. 

Before that, the parties will select candidates via primaries. There will be betting odds available for the most interesting and competitive among those.

At present, Republicans control both the House of Representatives and Senate. However, the betting now firmly favours the Democrats in the former, with Betfred offering the best price at 2/5, in contrast to just 11/50 with LiveScore Bet.

Trends Strongly Favour Democrats For The House

It is very hard to puncture Democrat claims here and, if anything, Betfred may be understating their chances in light of the results in the first week of November. They start 220-215 behind from 2024, with 218 required for victory, so only need to pick up three seats.

Those gains may become even easier after the Yes vote in California’s ‘Prop 50’ referendum. 

This grants the Democrat-controlled state the power to push through redistricting plans, devised by Governor Gavin Newsom in response to Trump’s demands that Texas alter their congressional district boundaries in Republican favour. 

Another court ruling in Utah on this matter also favoured the Democrats.

Moreover, it has become conventional for opposition parties to thrive in these ‘mid-terms’, with the party of the president losing every mid-term House election since 2002. 

And that one took place amid exceptional circumstances, with the electorate rallying around George W Bush following the 9/11 attacks.

As US politics has become ever more polarised over many decades, the dynamics of mid-term elections have been predictably affected, with the opposition better motivated to turn out. 

That’s what we saw in early November. Indeed all the signals from 2025 mirror 2017 - the first year of the first Trump presidency. In 2018, the Democrats swept to a ‘Blue Wave’ victory in the House.

Breaking Republican Dominance Looks A Tall Order

The Senate, however, presents a very different picture. The Republicans start here with a 53-47 advantage. Given that in the event of a tie, the Vice President holds the casting vote, the Democrats need to gain four seats in order to regain control of the Senate.

That would be a tough ask in any year. Senators are usually incumbents, with a long track record in their state and a name recognition advantage. 

If the party is struggling nationally, it is perfectly plausible that an incumbent Senator can stem the tide. 

Indeed, that is what happened in 2018. While Democrats dominated the House, Republicans held the Senate. Likewise in 2022, during the Biden administration, Republicans gained the House but fell short in the Senate.

Then there is the nature of the states in play to consider. It is not easy to find four pick-ups for the Democrats from the 2026 list. 

Maine is a decent chance or at the very least a toss-up. North Carolina also falls into the toss-up category. 

Iowa has leaned Republican for several years but many of their representatives are standing down there, including Senator Joni Ernst, and Democrats do have a history of competing there. 

Likewise, history makes Ohio a plausible longshot for them, assuming the national administration is unpopular.

Without winning all four, and holding their own marginal-held seats in Michigan, Georgia and New Hampshire, Democrats would need to pull off a huge upset somewhere else. 

Alaska and Kansas are probably next best on the list. It is no wonder, therefore, that bookies favour the Republicans for the Senate. Here, LiveScore Bet’s offer of 2/5 represents the best odds available.

Back Split Congress At 4/5

William Hill has an interesting market on the balance of power between the two branches of government. 

It prices a Democrat House/Republican Senate at 4/5. For the reasons laid out above, that looks plenty generous enough. The national and statewide trends in US politics are deeply entrenched.

Perhaps the big takeaway from this latest round of elections concerns the Republicans. 

It is now almost a decade since Donald Trump assumed leadership of the party, changing their direction and brand, while consuming almost all of the political oxygen. 

During that period, the Republicans have badly underperformed mid-term when Trump wasn’t on the ballot. 

That includes 2022 when, despite being the opposition, they failed to win the Senate and won the House by a much smaller margin than expected.

If the party has become something of a one-man band, that doesn’t bode well for either 2026, or the 2028 presidential election, for which he is assumed to be ineligible (even if prominent supporters argue he can and will run again). 

As it stands, bookmakers rate 2028 a toss-up, with 19/20 about the Democrats available with Star Sports, and Evens about the Republicans with one of the other betting apps.