Polls have opened across parts of the United States for Tuesday's pivotal midterm elections, featuring contests for all 435 House of Representatives seats and 35 of the 100 Senate seats. Voting hours are determined by individual states, with initial openings in states like Vermont, New Jersey, Virginia, Connecticut, and Kentucky.

These midterm elections are considered crucial as they could significantly alter the legislative landscape and impact the trajectory of the current presidential term. Historically, the party holding the presidency often faces challenges in midterm elections, with potential for significant losses.

More than 57 million Americans have already cast early ballots, with high turnout anticipated in key battleground states including Georgia, Michigan, North Carolina, Ohio, and Texas. Voters in 36 states will also choose their governors in separate elections.

The results of these elections will determine control of both chambers of Congress. Republicans currently hold a narrow majority in the Senate with 53 seats to the Democrats' and allied independents' 47. In the House, Republicans maintain a slim four-seat majority.

Democrats are campaigning on promises to address the nation's cost-of-living crisis and to end the current administration's foreign policy actions. They are seeking substantial gains in Congress that could reshape the political agenda for the remainder of the president's term. However, Republicans are working to counter these expectations.

Despite a historically low approval rating for the sitting president, hovering around 32 percent according to a recent poll, Republican candidates are relying on their base voters and a general distrust of progressive policies. They aim to defy the historical trend of midterm losses for the party in power.

Adding a layer of complexity to the races, a notable endorsement occurred Sunday when Haley Stevens, who lost Michigan's Democratic Senate primary in August, declared her support for Republican Mike Rogers over her party's nominee, Abdul El-Sayed.

These elections also occur against a backdrop of ongoing legal challenges, including a recent Supreme Court decision rejecting a request from former President Trump to set aside certain California ballots, a move aimed at preventing the counting of ballots from voters his administration claimed were not US citizens.