Not much about this toxic political moment – the demise of trust in government, rage at elites who have controlled a broken system, brutal personal attacks, a disregard for facts, and rupture besting unity – is likely to abate after Election Day. Then we get to do it all over again in four years.

At ages 70 and 69 by Inauguration Day in January, Donald Trump and Hillary Clinton would seem to be unlikely two-term presidents. Not only would Trump become our nation's oldest person elected president (after Ronald Reagan), but should Clinton win, she would become the second oldest. Perhaps more powerful than Father Time are the odds that neither of these two highly polarizing and disliked candidates can heal a deeply divided country and become a trusted leader. Against the backdrop of a nation reeling from a burgeoning terrorist threat, economic deterioration, and painful racial division, the campaigns of two singularly unpopular presidential candidates have left most Americans feeling emotions ranging from disappointment to despair.

Based on the examples of the George W. Bush and Barack Obama presidencies, we can expect the opposition party to savage the new president. Yet Trump or Clinton could also face revolt from within their own parties. While it wouldn't behoove them to declare anything publicly, and make themselves a lame duck, Clinton or Trump could reasonably conclude that leaving after one term is preferable to the stain of potential defeat. Much could change, but as of today Clinton appears to be the kind of politician bent on making her own historic mark, signing bills with whoever controls Congress, perhaps even defying her increasingly liberal party. Trump already appears ripe for a 2020 primary challenge, and seems to be someone who, at age 74, may prefer to return to the business world he has loved his whole life.

Should Clinton win, defying historical odds against bringing her party a third term in the White House, it would become incredibly difficult to keep it for a fourth. Republicans, far better positioned to win the White House in 2020, are already preparing themselves for a fierce competition that is sure to break out in the open in the early months of her administration.

A Trump loss would leave at least three factions within a broken GOP vying for supremacy – Ted Cruz conservative purists, Paul Ryan reformers and newly minted populists in the mold of The Donald himself: anti-free trade, immigration hardliners. Should Trump lose the election, we are likely to hear from him constantly, as leader of a large part of the Republican coalition, not only about Clinton's performance in office but about the next batch of GOP presidential candidates, which should feature both new and returning prospects. Expect more nicknames.

Should Trump win, but fail to unite his party in governing, he will face pressure from two factions hoping to depose him. The NeverTrumpers, both inside the conservative movement as well as the establishment, will not wait until 2020 to field candidates to challenge him. Cruz won’t even wait until Trump’s inauguration. Democrats would divide their time under a President Trump by trying to undermine his administration while vying for primacy and trying to define their party in a post-Clintons world. Sens. Bernie Sanders and Elizabeth Warren, as well as more moderate “Third Way” Democrats aligned with Clinton on trade and national security, will wage a fierce fight for power.

While intraparty rebellions and primary challenges have been successfully quashed in recent decades, the ideological cohesion that protected unity is fraying in both parties. A primary challenge is more likely in a volatile political climate where grass-roots rejection of party establishments is now bipartisan.

The possibility remains that Clinton or Trump could win and become successful presidents, however that “success” can be defined. But judging by the tenor of this campaign, voters won't have much patience with the next president, and therefore that person could have little honeymoon and far less time to win over those who voted against him or her.

The new president may not want to stand the heat for more than four years. Trump even teased, just last week, that he may not serve at all if elected in November. It could make the “permanent campaign” we have come to know seem quaint.