Image source, Bloomberg via Getty Images

By

North America correspondent

The Democratic Party has high expectations as it heads into these pivotal US midterm elections.

A historically unpopular Republican president, an American public unhappy with the rising costs of food and bills, and months of favourable polls point to a good night for them on Tuesday.

Democratic candidates lead in well over the 218 seats needed to flip control of the lower chamber of Congress, the House of Representatives, the polls suggest. And they are tied or narrowly ahead in the key Senate races.

A recent New York Times poll had the Senate race in South Carolina, a state Donald Trump won by 18 percentage points in 2024, as a tie. Recent CNN surveys put the Democrats ahead in Texas, Kansas and Maine.

But are the polls accurate?

Recent US political history is littered with examples where public opinion polls, even ones just days before an election, were off the mark.…