When Donald Trump became only president in our tangled history to be impeached twice, Americans found themselves asking, “What now?”

The better question is “What’s next?”

It goes beyond the prospect of a trial in the Senate that now appears set to unfold in the opening days of the new Biden administration, despite arguments over whether the chamber has such authority (there is hardly unanimity on that score).

Every move the nation makes between now and when the Senate votes on whether to convict Trump on charges of inciting insurrection will not only echo in the near term, it will set the tone for the next 20 years of our politics — and beyond.

Pundits have compared last week’s riot at the U.S. Capitol, which left five people dead, to Julius Caesar and his forces crossing the Rubicon river in Italy in 49 B.C., prefacing the civil war that ultimately toppled the Roman Republic.

The analogy is an imprecise one for a couple of reasons, not least because it does a grave disservice to Caesar, a master political strategist and brilliant (if utterly brutal) military commander. The oafish and authoritarian Trump can be accused of many things, but being a 21st-century Julius Caesar is not one of them.

If we’re looking for a more precise historical antecedent from the ancient world, we need to turn the clock back farther to the decades between the third Punic War in 146 B.C. that saw the final obliteration of Carthage, and the rise of the Caesars.

As historian Mike Duncan writes in his 2017 book “The Storm Before the Storm,” it was an era eerily similar to our own. One where the first cracks in the foundation of the Republic started to emerge.

Those years were, as Duncan notes, punctuated by “rising economic inequality, dislocation of traditional ways of life, increasing political polarization, the breakdown of unspoken rules of political conduct, the privatization of the military, rampant corruption, endemic social and ethnic prejudice, battles over access to citizenship and voting rights, ongoing military quagmires, the introduction of violence as a political tool, and a set of elites so obsessed with their own privileges that they refused to reform the system in time to save it.”

The era also was filled with colorful, controversial and historically influential figures who are understandably overshadowed by later emperors Augustus, Nero and Constantine. They include the Gracchi, a clan of populists who met a grisly end, as well as Sulla, who seized power through a military coup, setting the precedent Caesar followed when he finally toppled the Republic three decades later.

As the Cambridge historian Mary Beard writes in her compulsively readable 2015 history “SPQR,” the death of the last Gracchi brother in 121 B.C., set the stage for “three more sustained civil wars or revolutionary uprisings (there is often a hazy boundary between them).”

As terrifying and tragic as those hours at the Capitol were last week – and they were – it’s crucially important to note that hours later, the machinery of government reasserted itself and the House and Senate reconvened to certify the victory of President-elect Biden and Vice President-elect Kamala Harris.

The Capitol siege cast a light on an already present, and now growing, white nationalist movement that Trump, who is ignorant of history but savvy at manipulation, was able to turn to his political advantage to win the White House. And then, abetted by the conservative echo chamber, he weaponized them when his defeat was assured.

Now Washington and state capitals across the country have been bracing for a potential repeat of that violence during marches and protests over this week. We’ve already seen the images of scores of National Guard soldiers sleeping on the floor of the Capitol. We’re at a turning point in our politics. But it is not without precedent.

In his “Meditations,” one of the last great emperors, Marcus Aurelius, admonished readers (and himself) “to bear in mind constantly that all of this has happened before. And will happen again – the same plot from beginning to end, the identical staging.”

These are the historical realities that the Senate, which seems to have trouble thinking beyond the next news cycle, must keep in mind when it tries Trump. The government also must move swiftly to find, charge and try those responsible for the violence.

Fair trials, met with stern punishment for the guilty (which should include political banishment for Trump and rebukes to his enablers), will not only send the signal that our system remains strong and vital, but also remains a beacon for the rest of the world.

So that next time, when someone who might actually be able to pull it off thinks about crossing the Rubicon, they won’t get any further than the water’s edge.

An award-winning political journalist, John L. Micek is editor-in-chief of The Pennsylvania Capital-Star in Harrisburg, Penn.

jmicek@penncapital-star.com.