The US midterm elections... what are they What is its importance? The United States heads to midterm congressional elections on Tuesday, testing the performance of President Donald Trump and his Republican Party nearly two years into his term. All 435 seats in the House of Representatives are up for contest, while about a third of the 100 seats in the Senate are up for election. Republicans enjoy a slim majority in both chambers, and Democrats hope to seize it to hold the Trump administration accountable and limit its agenda. The elections also include races at the state and city level to elect governors, legislators and local officials v.aa.com.tr.