There is barely a week left before <a href="https://www.thenationalnews.com/world/us-elections">November 3</a>, when polls close in the most momentous American election in decades, if not a century or more. Fifty-six million ballots have already been cast by early and postal voting. If results are close, counting could go on for days and litigation for weeks. But a decisive outcome could be clear as early as election night. Democratic candidate Joe Biden's edge over incumbent Republican President Donald Trump has been amazingly consistent. Since early summer, he has held a strong, typically double-digit, lead in national polls, and smaller but significant ones in most swing states, with almost no deviation. Democrats are haunted by Mr Trump's unexpected victory over Hillary Clinton four years ago. Many Republicans appear convinced that he will somehow pull off another stunning upset. But with the economy struggling and the <a href="https://www.thenationalnews.com/uae/coronavirus">coronavirus pandemic</a> again surging, the underlying circumstances are radically different. Mrs Clinton was deeply unpopular, but there is no sign Mr Trump has provoked widespread dislike or mistrust of Mr Biden or demonstrated that he is senile or secretly radical. Early voting data heavily favours the Democrats. Yet Mr Trump could still win, particularly if he inspires a large group of those among his core constituency of non-college-educated white Americans who typically don't vote to go to the polls on election day. A marked surge of new Republican voter registrations in key states provides the main hope that he will prevail after all. The all-important Senate, meanwhile, seems a real toss-up and is now the main focus of serious Republican efforts. Four years ago, many Trump-backers cast the election in starkly existential terms. Now he is being even more lurid and aggressive, warning that a Biden victory would destroy the country, wreck its economy, prompt waves of non-white immigration, and hand power to radical socialists. This time, however, Democrats and numerous prominent disaffected Republican commentators and operatives (though few serving elected officials) agree that the stakes are historically and nationally existential. Mrs Clinton, by contrast, never took Mr Trump seriously until he won, and no one knew how he would behave in office. Mr Trump's campaign proclaims that American culture, capitalism and, in effect, white ethnic power are at stake. Mr Biden's allies insist that democratic institutions and the rule of law might not survive four more years of Mr Trump. The “soul of the country", both sides say, is on the ballot. The outcome will therefore force <a href="https://www.thenationalnews.com/opinion/comment/what-is-the-future-of-the-republican-party-if-donald-trump-loses-1.1055370">a far more dramatic reckoning</a> within the losing party than any normal defeat would. To counter Mr Trump's narrow but deeply passionate base, the Democratic Party and its own base voters strategically chose to unite, tack strongly to the centre and, through the staunchly <a href="https://www.thenationalnews.com/opinion/how-joe-biden-went-from-political-heavyweight-to-underdog-and-back-again-1.989737">moderate Mr Biden</a>, build the broadest national coalition they could, including by courting receptive conservatives. Democrats have bet everything on their centre-left mainstream leadership, essentially the old guard from the Bill Clinton and Barack Obama eras. They are basically offering Americans a return to pre-Trump “normality” through a familiar, moderate standard-bearer backed by a historically unprecedented bevy of his Republican former opponents who agree that democratic processes and institutions are in mortal peril from the current president. If Mr Biden wins, this gamble will be strongly vindicated and reinforced. As the clash between Mrs Clinton and Senator Bernie Sanders of Vermont four years ago demonstrated, there is a bitter Democratic split between a typically younger and passionate left-wing camp, and the centrist, often literally old, guard still in charge. That division will persist and perhaps grow. But a Biden victory will mean the new generation of leftists, now led by Congresswoman <a href="https://www.thenationalnews.com/arts-culture/alexandria-ocasio-cortez-played-among-us-in-a-bid-to-encourage-people-to-vote-1.1097186">Alexandria Ocasio-Cortez</a> of New York, must be patient. They can still pursue control of the party, but will have to proceed cautiously, given the success of the centrist gambit, and, especially at first, the glow of victory. But if Mr Trump wins, their ascendancy will be rapid. Amid bitter recriminations, the left would surely seize control of the party, shifting it radically in their direction. Among Republicans, as Mr Trump's presidency demonstrates, populist hardliners have already decisively defeated and marginalised the centre-right old guard, such as 2012 GOP presidential candidate Senator Mitt Romney of Utah. If Mr Trump is re-elected, this radicalism will be strongly reinforced, and his personal control become so entrenched that one of his own children may inherit his party leadership. If Mr Trump is narrowly defeated while loudly charging fraud, and especially if Republicans retain the Senate, the stage will be set for him to attempt a comeback in 2024, health permitting. Failing that, one of his core “America First” supporters – perhaps Senators Tom Cotton of Arkansas or Josh Hawley of Missouri, or the notorious white nationalist TV commentator Tucker Carlson – could take the helm of a doggedly extreme Republican Party. Even if he is trounced and Democrats take the Senate, a rapid resurgence of the beleaguered Republican centre-right seems unlikely. The base is now so extreme that what is needed is another programmatic Republican de-radicalisation campaign, even more extensive than efforts in the 1960s to marginalise the fanatical John Birch Society. Instead, former South Carolina governor <a href="https://www.thenationalnews.com/world/the-americas/three-key-moments-from-the-republican-convention-1.1068081">Nikki Haley</a> is poised to try to amalgamate populist Trumpians and traditional Reaganite conservatives. She has strong Reaganite credentials but served as Mr Trump's UN ambassador without alienating him or his base. Having painstakingly planted a foot in each camp, she has positioned herself to offer Republicans a viable future under a conservative, Christian woman of colour in an increasingly diverse country – a plausible opponent to another Indian-American, Mr Biden’s running mate and possible successor, Senator Kamala Harris. If Trumpism implodes in the coming days, a new Haley-led conservative fusionism could be the sequel. But there is no sign of any Republican leaders preparing to banish or subdue the increasingly empowered menagerie of fanatics, white nationalists, <a href="https://www.thenationalnews.com/opinion/comment/does-trump-honestly-believe-in-qanon-conspiracies-1.1067238">QAnon</a> and other bizarre cultists in their ranks. If Mr Biden loses, the US could be trapped between two extremist parties, with moderates sidelined in both. But if he wins, centrists and all Americans still committed to traditional institutions of democracy and the rule of law will retain a strong, even commanding, voice into the foreseeable future. <em>Hussein Ibish is a senior resident scholar at the Arab Gulf States Institute and a US affairs columnist for The National</em>