The fate of Donald Trump’s final two years in the White House will be decided on Nov 3. At the ballot box, American voters will determine the limits of his power.

The Democrats are widely expected to win the House, but the real fight will be for the Senate. The latest polls suggest they have a narrow edge in almost all competitive Senate races.

If they regain control of Congress, Mr Trump’s agenda would be derailed, leaving him to serve the rest of his term as a lame-duck president.

The Democrats have pledged an immediate 100-day agenda focused on holding a vote on the Iran war, cutting health care costs, undoing Mr Trump’s tariff regime and triggering investigations into the ethics of Mr Trump and his administration, their immigration enforcement agenda and the conflict with Iran.

Hakeem Jeffries, the Democratic leader, who is in line to become Speaker of the House if the party wins, called Nov 3 “judgment day”.

“I refer to November 3 not just as election day but judgement day, because in three days the American people will judge the Maga extremists and run them out of town,” he told a rally on Saturday.

Donald Trump promised $5,000 to every American adult if Republicans retain control of Congress in November Midterm elections happen two years after the election of a president – halfway through their tenure – and determine which party controls Congress. There are two chambers in Congress: the House of Representatives and the Senate, the lower and upper chambers respectively.

Midterms almost always serve as a referendum on the president’s party, and losses typically ensue. Republicans lost around 40 seats in 2018.

If the president’s party loses majorities in the chambers, it becomes very difficult to pass legislation.

A key issue in this year’s midterms has been redistricting, with several states redrawing congressional maps to swing the balance of power in House races.

All 435 seats in the House of Representatives will be up for reelection, while 35 out of 100 seats in the Senate are being contested, which includes two special Senate elections in Florida and Ohio.

Each of the 50 states has two senators. Office holders are elected for six-year terms on a rolling basis, meaning that every two years, one-third of the senators come up for reelection. Representatives instead serve two-year terms, meaning they are all up for grabs. Republicans currently control the White House and have slight majorities in both the House and Senate.

The Democrats need to net only three House seats to take the majority. To win a Senate majority, Democrats need to defend all their current seats and flip at least four more.

Americans will vote for all 435 seats in the House of Representatives that will be up for re-election, and 35 out of 100 seats in the Senate are being contested The closest Senate races are in Alaska, Iowa, Kansas, Maine, Michigan, Ohio, and Texas.

The nonpartisan Cook Political Report rates Senate races in those states as toss-ups, meaning either party has a realistic chance of winning.

All but Michigan are currently represented by Republicans. Mr Trump also won five of the states by double-digit margins in 2024.

If Democrats win all seven races, as well as those in which they are favoured to win, including North Carolina, they would secure their largest Senate majority since the Obama administration.

In Michigan, hard-Left Democrat Dr Abdul El-Sayed is up against Republican Mike Rogers to replace retiring Democrat Senator Gary Peters.

Democrats are hopeful Dr El-Sayed, a progressive candidate critical of Israel, will emerge victorious. On Sunday, his campaign was rocked by his former primary rival, Haley Stevens, defecting from the Democrats and endorsing Mr Rogers.

Dr Abdul El-Sayed is the Democratic nominee in the Senate election in Michigan The Maine race also faced a lot of publicity after Democratic candidate Graham Platner dropped out following accusations of sexual assault by a former girlfriend, which he denies. Maine Democrats picked Troy Jackson as their nominee on July 25,justthree months before polling day.

In Texas, Mr Trump swung his weight behind Ken Paxton at the last minute, helping him defeat Senator John Cornyn, a four-term GOP incumbent, causing a split in the Republican Party.

Mr Paxton will go up against Democrat James Talarico, who has faced scrutiny for earlier progressive statements on gender and religion made during his time in the Texas legislature, including that God was non-binary, but has since moderated his positions.

In Republican-leaning Alaska, incumbent Senator Dan Sullivan is seeking a third term, and will go up against Mary Peltola, a former representative, who finished first in the state’s non-partisan primary.

If Ms Peltola were to win, it would be the first time a Democrat was elected to the Senate in the state since 2008.

Kansas has seen recent visits from Mr Trump and JD Vance, an indication of the GOP’s jitters in a state where Republican candidates have dominated federal elections for generations. Republican-turned-Democrat challenger Adam Hamilton has steadily chipped away at the GOP incumbent’s lead in the polls.

Kansas is one of several rural states, once traditional Republican strongholds, where farmers are expressing discontent over the soaring cost of diesel and fertiliser caused by the Iran war and could swing blue.

In Iowa, Republican Ashley Hinson will go up against Democrat Josh Turek to replace Senator Joni Ernst, the retiring Republican senator. What are the main issues for voters?

The economy remains the key issue for most voters, according to the Pew Research Center. Mr Trump’s war with Iran has pushed gas prices up and driven up the cost of food and health services, while the country’s national debt reached a record $40tn (£29.6tn) on Aug 18.

Mr Trump’s war with Iran has pushed gas prices up and driven up the cost of food and health services, while the country’s national debt reached a record $40tn His tariff policies have also been deeply unpopular and caused rifts with other countries, including Canada. This has affected Republicans’ confidence, even in seats they considered safe.

According to The Economist, the most important issues for both Democrats and Republicans are inflation, jobs and healthcare.

While Mr Trump’s Republican base is very concerned with immigration, taxes and government spending, Democrats are more worried about healthcare and climate change. His approval is between 32 per cent and 40 per cent, according to national polls days before the elections.

In the seven key states determining control of the Senate, just 38 per cent of likely voters approved of the president’s job performance, according to the final New York Times and Siena University poll.

Mr Trump has the lowest polls of his presidency, largely owing to the unpopularity of the Iran War Jonathan Monten, a political science professor, told The Telegraph that Mr Trump may not be dreading an expected “blue wave”.

He does not have a legislative agenda he is trying to push through Congress, but is largely operating with executive orderand the power of the presidency, with the tariff agenda and war in Iran both being conducted through presidential powers.

“If he loses a majority in Congress, he doesn’t have legislation at stake,” said Mr Monten.

“It is more about the balance of electoral power right now and whether Democrats will be able to push for accountability. They would control the budgets and Congress’s investigative control committee and start to have real levers.”

However, it would stymie the president’s ability to pass legislation such as the Save America Act to tighten voting laws, which he has said: “supersedes everything else.”What do the latest polls say? Democrats are favoured to win control of the House.

For the Senate, recent polling gives the Democrats a slight advantage in six of the seven battlegrounds.

Democrats have a lead in Michigan, Texas, Kansas, Maine and Ohio, a narrow edge in Alaska, and are tied with Republicans in Iowa, according to the latest polls by The New York Times and Siena University. Texas has not elected a Democrat to the Senate since 1988, and Kansas has not elected one since 1932.

The Washington Post averages of all recent high-quality polls in each state also showed narrow leads in all seven toss-up Senate races. There is still some cause for concern over undecided voters and which way they will swing.

If dissatisfaction with Mr Trump and the Republican Party means the Democrats win power in either the House or Senate, then power will quickly seep away from the president.

It means those GOP contenders who hope to concede to him will have a difficult balancing act: distancing themselves from an unpopular incumbent, without provoking him into criticising them for their disloyalty. JD Vance, the US vice-president, could find that particularly hard to navigate.

JD Vance will have a difficult task navigating his relationship with Mr Trump if the Democrats win power in either the House or Senate At the same time, a Republican sweep would further embolden Mr Trump and concentrate his power as a kingmaker who can anoint a successor.

If Democrats fail to win a majority in at least one chamber of Congress in spite of Mr Trump’s dire poll ratings, it will prompt a reckoning within the party.

However, midterms do not always define the presidential election. The disaster faced by the Democrats in the 2010 midterms did not prevent Barack Obama from winning reelection in 2012, for example.

Likewise, although the Republicans’ predicted “red wave” did not materialise in 2022, Mr Trump stormed back two years later to win the presidential election and every swing state.

If they win control of the House, Democrats are planning a 100-day agenda aimed at cutting living costs and launching investigations into alleged corruption within the Trump White House.

“Fighting for an affordable America – that’s what unites Democrats all across the country,” said House minority leader, Mr Jeffries, earlier this month.

“That’s our commitment to the American people, because the cost of living is way too high and far too many people who are working hard, playing by the rules, can’t thrive and can barely survive – and are drowning – in the Trump economy.”Democrat Hakeem Jeffries is in line to become House Speaker if his party wins a majority The plan includes reinstating healthcare tax credits that expired in 2025, leaving millions of Americans facing higher insurance bills.

It also envisages reversing Mr Trump’s tariff policies and pressuring the US president to end the war in Iran.

Mr Jeffries has instructed senior Democrats on the House oversight and judiciary committees to prepare corruption investigations focusing on the Trump family and his inner circle.