Americans cast their ballots in high-stakes and unprecedented election

Millions of Americans will cast a ballot on Tuesday as polls open across the country to wrap up what is expected to be one of the closest presidential races in U.S. history after a historic and unprecedented year in politics.

The presidential race between Democratic Vice President Kamala Harris and Republican former President Donald Trump has come down to the after several shocks to the race and little evidence from pollsters that has shown either with a clear advantage in any of the swing states that will decide the winner.

Harris and Trump agree on next to nothing on most of the political and cultural issues that separate the parties in an increasingly divided and partisan electorate, offering very different paths forward for the country depending on who wins the Oval Office.

It's unclear who the winner will be headed into Election Day and also uncertain is when it will be known with several critical battleground states likely to take days to tally all the votes.

Out of tens of millions of votes across the country, the race may be decided by margins of just thousands in seven states — Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin — that have received the overwhelming majority of both presidential campaigns' attention and advertising dollars over the last few months.

While it could take days to know the outcome, voters will decide which of them will head to the White House for the next four years on Tuesday, though it comes after the most unpredictable whirlwind year that was filled with unprecedented events that shook the country and political landscape to its core.

Trump handily won his third consecutive Republican presidential nomination, cruising through primary season as his challengers dropped out of the race as it swiftly became apparent that the party's voters would nominate the former president. But that outcome was always obvious, having left office at a low point with the Jan. 6 riot at the U.S. Capitol that was followed up by a poor showing for the party in the 2022 midterms that had some Republicans calling on a new standard-bearer to lead the party forward and four criminal cases that included one conviction against him, making him the first former president to be convicted of a crime.

Despite all the headwinds, Trump glided to the nomination and all but ignored his primary challengers, skipping debates and diminishing their campaigns along the way. He focused much of his attention on the administration of President Joe Biden, tuning into voter frustration about inflation and fears about the state of the economy while bashing his handling of the U.S.-Mexico border and saying Biden was too old to serve another four years as president.

While the race was generally close in polling headed into the summer, momentum shifted in Trump's favor after the June 27 debate with Biden, whose disastrous performance exacerbated preexisting fears about his age and mental acuity and sparked a political crisis in the White House as more Democratic lawmakers and figures publicly called on him to drop out of the race.

As Biden was trying to bat away suggestions he should drop out of the race, it was hit with another shocking event when while speaking on stage during a July 13 rally in Butler, Pennsylvania by a teen with a gun who was able to avoid police and get access to a rooftop with a clear sightline to the stage, also killing a rallygoer and injuring two others.

The first time a president or presidential candidate had been shot in decades, it was an event that stunned the nation and shellshocked the presidential race as images of Trump with blood across his face and a fist raised as he shouted "fight, fight, fight!" with an American flag over his head circulated online and in the news.

While the dynamics of the race were still be sorted out in the wake of the assassination attempt, Biden made the on July 21, suddenly propelling her to the Democratic nomination as the party quickly coalesced around her.

Securing the nomination just a couple days later, Harris then started out on a 106-day sprint toward Nov. 5 with a campaign made up mostly of Biden's staff and infrastructure as she tried to turn the party's fortunes around.

Her campaign has tried to capitalize on the political momentum the 2022 overturning of Roe v. Wade for Democrats and tried to draw contrasts between herself and Trump on personality and policy. Harris has also tried to cast a wide net in terms of appealing to voters from Democrats to independents and even some of the Republicans who are hesitant to support the former president.

At the end of her 100-plus day sprint to Election Day, she has successfully brought the race to a toss-up from a struggle for her party and outperformed her last attempt at the White House during the 2020 primaries where her campaign stalled out before making it to Iowa.

While the top of the ticket gets the most attention, control of Congress is also up for grabs on Tuesday as voters across the country will cast ballots for all House representatives and 34 seats in the Senate to decide which party controls each chamber and the government along with the White House.

The to take a slim majority once all the votes are tabulated with all of the most competitive seats being held by retiring Democrats or being in red-leaning states that provide flip opportunities for the GOP.

The Senate map for Democrats includes 23 seats to defend, several of which are in Republican-leaning states who voted for Trump in 2020. and Jon Tester of Montana are facing challenging reelections serving as Democrats in red states, and the retirement of West Virginia Sen. Joe Manchin has essentially guaranteed Republicans one flip.

Democrats are also on defense in other presidential battlegrounds including Nevada, Arizona, Wisconsin and Pennsylvania. Meanwhile, Republicans only have a handful of seats that could flip in Florida, Texas and Nebraska, though all are considered to be longshots.

Sen. Ted Cruz of Texas is facing a tight reelection bid against Democrat Colin Allred in a race that has slightly favored the GOP incumbent but has been separated by narrow margins in polling heading into Election. The state's heavy Republican tilt has started to shift over the last several years, sparking some optimism its Senate seats and Electoral College votes could become competitive moving forward.

In Nebraska, Republican Sen. Deb Fischer is against independent Dan Osborn as Democrats have opted against running a candidate in the race. With a tight Senate race and a unique system of allocating Electoral College votes, Nebraska could have an outsized role in determining the balance of power in Washington despite its heavy Republican tilt overall.

Control of the House is a toss-up heading into Election Day with roughly two dozen swing districts that will likely determine which party controls the lower chamber over the next two years along with others that forecasters have rated "lean" toward either party, indicating that they will be closely decided.

Control of the House traditionally closely follows the results of the presidential election as is more likely to do so this year due to the breakdown of the Senate map that has fewer swing seats up for grabs.

California and New York could be decisive in determining which party has a majority despite being safe for Harris in the Electoral College. Between the two states, there are 12 seats that are considered toss-ups or lean toward either party, which could decide the balance of power in a closely divided House.

Ohio, Iowa, Pennsylvania, Michigan and Arizona are other states with multiple seats that are expected to be closely decided and could fall in line with the presidential election.