Control of the US Congress is at stake in elections that could flip both the House of Representatives and the Senate, while still leaving Capitol Hill divided between Donald Trump’s Republicans and Kamala Harris’ Democrats. The outcome will play an important role in determining how easily the winner of Tuesday’s US presidential election will govern until the next congressional elections in 2026. Nonpartisan analysts say Republicans stand a good chance of taking back the Senate, where Democrats hold a 51-49 majority. But Republicans could also lose their grip on the House, where Democrats only need to pick up four seats to take back control of the 435-seat chamber. As in the presidential election, the outcome will likely be determined by a small slice of voters. The battle for the Senate hinges on seven contests, while fewer than 40 House races are seen as truly competitive. Voters do not seem to be indicating a clear preference for either party. An October /Ipsos poll found 43 per cent of registered voters would back the Republican candidate in their district, while 43pc would back the Democratic candidate.