Control of the House rests on a knife's edge

Across the United States, there are around 20 'toss-up' races that will decide which party has a majority in the House.

The basics of House elections

There are 435 House districts across the US, allocated to states proportionally based on population. The entire House of Representatives is elected every two years, which makes campaigning for the next election an essential piece of the job. Members of the House have to raise thousands of dollars every day to stay competitiv…