// BBC WORLD NEWS — MONDO
Where the US midterm elections will be won and lost
Americans head to the polls on 3 November to decide how the rest of Donald Trump's presidency will play out.
Thousands of races are taking place across the US, at different levels of government. But the main event for voters will be electing members of the House of Representatives and the Senate, the two chambers that make up Congress.
Both of them are currently controlled by the Republicans, the president's party. The success or failure of Trump's final two years in office could rest on the outcome.
Here's our visual guide to where the battle for power will be won and lost - from approval ratings, to key races and issues and the huge amount of money being spent.
One of the reasons the opposition Democrats have a chance to take back Congress is the president's low approval rating, which is a good indicator for how well his party could perform.
He began his second term as president with an approval rating of just over 50%, according to polling resource website Silver Bulletin, but it quickly fell into the 40s.
It was hovering around 42% when Trump decided to launch air strikes with Israel against Iran at the end of February this year but it fell below 40% shortly afterwards. It is currently sitting at about 37%.
Eight years ago, Trump's approval rating was significantly higher at this point in his first term, at 43%. Joe Biden's at the same point in his term was at 40%. In both cases, the sitting president lost control of the House in the midterms but kept hold of the Senate.
But Trump's poor ratings help explain why Democrats are hopeful of winning both chambers of Congress and why they are setting their sights on states that Republicans have won consistently in recent years.
The current Republican majority in the House of Representatives, the lower chamber, is as thin as it gets - they have 218 representatives, which is the exact number needed to have control, plus one independent who votes with them.