Voters in the United States on November 3rd will elect members of Congress, which is made up of two parts – the House of Representatives and the Senate.
These elections happen midway through the term of the US president – two years after the presidential elections – and determine which party controls Congress.
The outcome is important because if the president’s party does not hold a majority, it becomes difficult to pass legislation.
A key task of Congress is to create and pass federal laws – laws that apply nationwide.
RM Block
The outcome will determine which political party – Donald Trump’s Republicans or opposition Democrats – controls Congress and how easy the US president can advance his agenda.
The results are also seen as a barometer of public opinion on the US president’s performance to date.
Trump’s overall approval rating has been falling for months, according to data from Real Clear Polling, down from a high of 48 per cent when he was inaugurated.
A key factor behind his successful 2024 presidential election campaign was his pledge to tackle the cost of living, posing with eggs and other household staples.
Two years on, many voters are struggling with the price of fuel, groceries, housing and healthcare. Data from the polling site Strength in Numbers shows Trump’s approval ratings have been trending in a negative direction on these issues for some time.
Who, exactly, is being elected?
All members of the House – which is the lower chamber of Congress – will be elected. The 435 representatives serve fixed terms of two years.
To gain control of the House, a party needs a minimum of 218 seats. The Republicans hold a narrow majority after winning 219 seats in the 2024 elections.
It will only take a few seats to flip and the power dynamics of the House will look very different.
Latest polling indicates that Democrats are likely to win the House.
In the Senate – the upper chamber of Congress – just 35 out of 100 seats are up for grabs.
The Republicans hold 22 of these seat and Democrats 13.
To take back control of the Senate, the Democrats must flip at least four seats, including two in states where the president won by double digits. They also need to keep all of their seats.
Each of the 50 states has two senators. Office holders are elected for six-year terms on a rolling basis. Every two years, one-third of the senators come up for re-election.
Democrats are growing increasingly bullish about their chances of winning seats, even in red states such as Texas and Iowa.
What are the key states to watch?
Many seats in both chambers are not competitive because they are located in Republican or Democrat strongholds.
Most observers believe that between eight and 10 states will be competitive and could prove pivotal once the results are tallied after polls close on November 3rd.
They include Alaska, Georgia, Iowa, Kansas, Maine, Michigan, New Hampshire, North Carolina, Ohio and Texas.
Keith Duggan, our Washington Correspodent, has been visiting many of these swing states. You can read his articles here.
Voting has been made more unpredictable this year because of redistricting, with several states redrawing congressional maps to swing the balance of power in House races.
Other unusual factors include Trump’s pledge to pay voters $5,000 if Republicans maintain control of Congress, as well as eye-watering sums of money being spent on campaigns in some toss-up states during the final weeks.
What do the opinion polls say?
Since the start of 2026, most polls have given the Democrats a lead nationally.
Polling, however, has tended to understate support for Trump. In 2024, for example, most polls pointed to a Kamala Harris victory in the presidential elections. In the end, Trump won comfortably. Polls also underestimated Trump’s support when he beat Hillary Clinton in the 2016 presidential elections.
Many betting sites or, increasingly, prediction markets have been more accurate.
According to one of the market-leaders, Polymarket, most people who have placed bets are confident that a Democratic sweep of the House and the Senate is the most likely outcome.
How might the outcome affect Trump?
If the Democrats win either the House or the Senate then Trump will find it difficult to get laws through Congress.
While some of his domestic plans could be frustrated, the US president has found ways to exercise executive power without his wider party.
Democratic control of either chamber would mean they could use committees to investigate aspects of the Trump presidency.
This could have knock-on effects for the Iran war, funding for Israel and Trump’s political future. Democrat control could mean investigations into the Trump administration.
If the Republicans continue to control Congress, Trump will be able to continue with his plans and policies for the remainder of his time in office.
Read more:
Some of Keith Duggan’s latest articles on the US midterm elections:
[ Emerging Democrat star Jon Ossoff has become a chief thorn in Trump’s sideOpens in new window ]
[ Lone star Trump believes he can bend Texas and midterm elections to his willOpens in new window ]
