Seneca entreated us to spare a little time each day to think of everything that could go wrong: “Reckon on everything, expect everything. Nothing ought to be unexpected by us.” Our minds should consider all scenarios: not just what is wont to happen, but what can happen.

Try as we might, we can’t seem to get comfortable with the consensus around the US election.

It’s hard to pinpoint precisely, but something does not feel right. We have come to rely on our intuition to avoid systematic errors in thinking. Oftentimes we start with some intuitive knowledge, which later can be validated or invalidated through rigorous research and analysis.

It was only in January that President Trump was hailed as the strongest incumbent ever to face reelection. Joe Biden’s depiction as a lackluster contender contrasted with Bernie Sanders’s surge in popularity. Betting markets gave the Vermont senator a 60 percent chance of winning the nomination.

A hasty unity among center-left Democrats who were disinclined toward a progressive political revolution propelled Biden from electoral failure to presidential nominee on Super Tuesday. Was the former vice president the most electable candidate the Democrats could rally behind? It was baffling. The party seemed to be in disarray. 

A nearly universal lack of enthusiasm for Biden was twinned with skepticism about his ability to beat Trump. (Only Sanders could put up a good fight against the president, we believed, by mobilizing young voters.)

The coronavirus pandemic was a turning point. Trump’s fumbled response gave Biden the election advantage. People started believing that Biden could win. Races tightened even in traditionally red states like Texas, Montana, and South Carolina.

Once Kamala Harris joined the Democratic ticket as vice presidential nominee in August, the narrative became more powerful. A sizeable lead in the polls bolstered Democrats looking for an election sweep. Wall Street strategists put forth a bullish argument for stocks, putting aside Biden’s commitment to raising corporate taxes and increasing regulation.

The farcical first presidential debate laid bare Trump’s “psychotic unraveling,” as conservative writer Andrew Sullivan put it. He was crashing in the polls. In the face of his Covid diagnosis, some said that he may die before the election. People focused on the presidential line of succession. House Speaker Nancy Pelosi backed legislation to determine whether a president lacks the mental or physical capacity to carry out the job.

As we write, Biden’s nationwide lead over Trump has risen to 9.7 percent, according to an average of polls by RealClearPolitics. Democrats are ahead in all of the nine key battleground states. Among the likeliest scenarios from Nate Silver’s FiveThirtyEight polls is now a Biden electoral college victory of over 400. The blue wave is turning into a tsunami.  

In just over six months, then, a storyline that started with I-can’t-believe-Biden-is-the-nominee shifted drastically; he won’t win; he can win;