Five reasons why Republicans lost so badly

Americans are electing members of Congress, which is made up of the House of Representatives and the Senate. All 435 House seats are up for election. In the Senate, only 35 of 100 seats are being contested because senators serve six-year terms.

This results tracker shows both the races being decided now and the 65 seats that are not up for election this year - 34 held by Democrats and 31 by Republicans. While the incumbent president's party generally tends to have a bad night in these elections, the scale of the Republican defeat is being viewed as a resounding rejection of Donald Trump's two years in the White House. From coast to coast, voters across the US have been grappling with the soaring cost of essentials.

That anger was palpable on the ground in key races. "Gas prices, grocery prices, everything's going up," one North Carolina voter told the BBC ahead of the elections, adding that she had switched her vote from Republican to Democratic this election. Prices increased by 3.7% in the year to September, driven higher by fuel and energy prices.