With early voting and absentee ballots increasingly common, millions of Americans will be casting their votes in the 2020 presidential election in less than one year. Election Day itself is November 3, 2020, which means we are barely a year away from choosing a president.

The answer to the big question — “who will win the election?” — is a function of the answers to a series of smaller questions. The first set relates to the Democrats who are running against President Trump.

“Can Biden hang on?” Relatedly, “Is Biden too old?” Vice President Biden will turn 77 on November 20. He has been at or near the top of the polls since entering the presidential race, despite mediocre debate performances and extensive press attention to his son Hunter’s work, for undisclosed fees, as a board member of Burisma, a Ukrainian energy company.

“Will a late entry emerge?” Secretaries Clinton and Kerry and Mayor Bloomberg have all been the subject of recent speculation that they would parachute into the race. Though the press would love it, this scenario strikes me as unlikely. It’s just too late.

Mrs. Clinton already lost once to Mr. Trump. Mr. Bloomberg is older than Mr. Biden and is too rich for a party whose voters think rich people are already too powerful. Mr. Kerry doesn’t offer any advantages over Mr. Biden in the old-white-guy-former-senator Democratic candidate category and has the disadvantage of coming off as more of a pompous scold.

“Will Sanders throw his support to Warren?” The heart attack that struck Senator Sanders had a lot of people doing figuring out that if Mr. Sanders’ support in the polls were added to that of Senator Warren, the combination of the two left-leaning candidates might be enough to defeat the more moderate Mr. Biden in the primaries. Unless the health of Mr. Sanders, who is 78, significantly deteriorates — there is no evidence that it will — this, too, is an unlikely scenario, as unlikely as Mrs. Warren throwing her support to Mr. Sanders.

“Will Buttigieg break out?” The 37-year-old mayor of South Bend, Indiana, Peter Buttigieg, is hoping to challenge Mr. Biden as the moderate, unifying candidate who isn’t as far left as Mr. Sanders and Mrs. Warren. He has seen fundraising success, and recent polls show him gaining some traction.

Part of his fate will depend on whether he can win over voters like a woman I met at a Biden rally in New Hampshire. Asked about Mr. Buttigieg, she replied that if America wasn’t ready to elect a woman president, as she figured Hillary Clinton’s defeat demonstrated, it probably isn’t ready to elect a gay president. Yet this is the same country open-minded enough to elect a candidate named Barack Hussein Obama. So you never know.

“Can Warren surmount the ‘electability’ concerns?” To beat Mr. Biden, Mrs. Warren will have to address the concerns of voters that she has staked out far-left positions on so many issues that they will alienate the voters she needs to win a general election.

Democratic voters don’t necessarily disagree with Mr. Warren about abolishing private health insurance, getting America out of the Middle East, decriminalizing illegal immigration, imposing a wealth tax, and so forth, but at least some of them have an accurate-enough sense of the rest of America that they doubt these are positions on which a law professor from Cambridge, Massachusetts, can win over a majority of general election voters in Pennsylvania, Wisconsin, Florida, and other swing states.

“What will the superdelegates do?” The primary campaign is a race for delegates. National survey numbers matter, but the nomination is won by delegates. A significant number of those delegates are determined not by primaries or caucuses but are senators, congressmen, governors, or Democratic National Committee members.

The rules have changed since Mrs. Clinton used the superdelegates to her advantage, but in a contested convention, they could be decisive. Watch to see whether the many members of Congress who have so far held back from endorsing a presidential candidate wind up consolidating behind either Mr. Biden, Mrs. Warren, or a Biden-alternative such as Mr. Buttigieg.

The next set of questions relate to Mr. Trump.

“Is the impeachment inquiry going anywhere?” I don’t see a Republican-controlled Senate providing the votes necessary under Article I of the Constitution — “two thirds of the members present” — to convict Mr. Trump with less than a year to go until the election. Reasonable people may disagree with the concept or execution of a Trump administration effort to link America aid to Ukraine to that country’s investigation of possible corruption involving Hunter Biden.

The idea that it warrants throwing a president out of office with less than a year to go before the election, though, seems weird. The likelier outcome is a decision to let the voters, rather than the Senators, weigh how serious a problem the Ukraine story is, if it is a problem at all, in the context of the rest of Mr. Trump’s strengths and weaknesses and in the context of the possible alternative occupants of the oval office.

“Will relative peace and prosperity endure”? With the stock market at new highs, unemployment rates at recent lows, and Mr. Trump pressing the Federal Reserve to keep that all going past the election, the best the Democrats seem to be able to muster against Mr. Trump is that people shouldn’t have to work two jobs to make ends meet.

The political potency of the “too many jobs” attack remains not fully tested, but I doubt it’s as strong as “not enough jobs.” As for national security and foreign policy, absent a high-profile terrorist attack, it doesn’t seem high on the list of most voters’ concerns.

“Is unpopularity fatal?” Significant numbers of Americans don’t merely disagree with Mr. Trump, they are embarrassed of him, finding him racist, uncouth, distasteful, a threat to democracy. That phenomenon could get Mr. Trump fired by the electorate if he doesn’t have an effective strategy to defuse or address it.

The columnist’s job isn’t only to raise questions but to attempt to answer them. My own sense of it, a year out, informed by a prediction market in which people bet their own money? Get ready for four more years of President Trump.