The outcome of America's deadlocked, deadlocked presidential election is impossible to predict, but the contours and consequences of the bitter, sometimes rancid and seemingly endless campaign are already clear.

Americans' decisions in Tuesday's presidential campaign will continue the dramatic transformation of two major parties that, like the country itself, are undergoing massive change. In an unlikely and awkward tandem, both parties have simultaneously discarded their past, reconfigured themselves and together are imagining a political future entirely different from the one that has dominated the country for generations.

Regardless of who prevails, voters flocking to the polls to choose between two candidates who have adjusted their profiles in recent years are also engaged in a separate, far-reaching process: consolidation or even acceleration the changes in the Republican Party and the Democratic Party, which respectively nominated Donald Trump and Kamala Harris and sent them into this year's election campaign.

“There has definitely been a shift in party coalitions along income, geographic and educational lines,” said Matt Grossman, director of the Institute for Public Policy and Social Research at Michigan State University in one of the seven critical swing states. “This election solidifies those coalitions, and that is particularly evident here in Michigan.”

The latest New York Times/Siena College poll puts Michigan, which has 15 electoral votes and was a particularly hotly contested battleground in the final days of the campaign, at a 47-47 percent tie. The Times/Siena poll puts Pennsylvania, which had the largest swing state victory in Tuesday's vote with 19 electoral votes, at a 48-48 tie.

In both places, as across the country, the content of American politics is shaped by questions of identity and culture.

“The mainstream media constantly wants to attribute voters' preferences to the economy, but what might really matter this time are voters' identities beyond economics, particularly education levels and gender,” said David Shumway, an expert on cultural forces who teaches at Carnegie Mellon University in Pittsburgh. “We sometimes think that Democrats are defined by identity and culture, but the entire Trump movement is rooted in identity and culture.”

Republicans and Democrats have been trading places at the top of American politics and their constituencies for 168 years – since the emerging Republican Party first faced off against the established Democratic Party in 1856 in an election that was a precursor to the Civil War.

The two parties have been at a virtual stalemate for the past quarter century, with one party following the other in the White House, with Congress generally so divided that major legislation rarely occurred. Over the past 25 years, vice presidents, who have the power to break ties in the Senate, have cast the deciding vote in the chamber an astounding 55 times. In all of American history, this has only happened 301 times.

Along with the presidency, control of both chambers of Capitol Hill will be decided on Tuesday, with the likelihood that Democrats will end GOP rule in the House and Republicans will oust Democrats from control of the Senate.

Although Mr. Trump talks about making America great again, his emergence as a formidable force in American politics is as much a full-scale rebellion against the recent past as a movement determined to shape the American future. It represents a rejection not only of the Democratic Party but, just as importantly, of the Republican Party.

By attracting American workers who had once sworn unwavering loyalty to the Democratic Party, he shattered a governing coalition that controlled the House of Representatives for four decades without an interregnum; that gave U.S. presidents like Franklin Roosevelt and John F. Kennedy, whose images hung for decades on the parlor walls of miners, steel workers and urban strivers, portraits that in some cases still exist today; and that gave the country Social Security for the old, the Great Society for the poor, and Medicare and Obamacare for the sick.

By driving the country's traditional conservative elite from their familiar home in the Republican Party of Calvin Coolidge, Dwight Eisenhower, George HW Bush and even the disgraced Richard Nixon, Mr. Trump has claimed the disenfranchised, the alienated and working-class voters, who were once the foundation of the Democrats. He also destroyed the Republican tradition of caution, prudence, personal and public responsibility, and sound judgment that acted as a brake on liberal excesses and, with the exception of Nixon, demonstrated the power of character in American civic life.

As these changes unfold – bringing with them likely changes in the leadership of Capitol Hill and the replacement of Joe Biden in the White House – the changes in the character and composition of the parties will become clearly visible.

“Parties change over decades — that’s normal — and we accept the idea that there is fluctuation,” said Tom Corbett, a Republican who served as Pennsylvania’s governor from 2011 to 2015. “Both parties go to their extremes. The MAGA people who lead my party are too far to the right. The Democrats are too far to the left. I don’t recognize the people who took over my party.”

At the same time, former Democratic Party Chairman Paul Kirk is amazed at the makeup of the party he led from 1985 to 1989.

“The Democratic Party was full of people who loved FDR, Harry Truman, JFK and Lyndon Johnson, and in both of his elections, Ronald Reagan stole them and many of them never came back,” said Mr. Kirk, who served in the Senate Massachusetts 14 years ago. “In addition, there are the former Democrats who now vote Republican for cultural reasons. They don’t like what they see in the party and believe it wasn’t what made them or their parents and grandparents Democrats for decades.”

The result is that the Democratic Party has lost its old base, the Republican Party has lost its luster of sobriety, and the country, clinging to a political system that only creates a clash between two parties, appears to be drifting and sailing in the same direction of uncertain, dangerous waters that the poet Walt Whitman spoke of when he wrote in 1849, when the country was convulsed by the slavery issue a dozen years before the Civil War: “Humanity with all its fears/With all the hopes of future years.” ,/ Hangs breathlessly on your fate!”

Ms. Harris will also be remembered as a groundbreaking figure, even if the results of Tuesday's election don't take her to the Oval Office, nuclear legislation and weekend trips to leafy Camp David in the Maryland mountains.

There has been little talk this campaign about whether “America is ready” — the phrase attached to every breakthrough in the country’s history, whether successful or not — for a black woman president. It is clear that America is ready for a candidate with Ms. Harris's gender and ethnic profile. The remaining question is whether Ms. Harris is the one to break the barrier. When the polls close on Tuesday, the answer will take shape.