Call me a wide-eyed optimist, but I have a feeling that even if President Trump makes it through his first term, the Republican Party might not want to renominate a man who was negotiating a high-stakes deal with an adversary of the United States while running for president — and lying to us that he was doing no such thing. Forget the possible crimes and impeachable offenses for a moment. Isn’t the raft of new information about Trump a major problem if he runs in 2020? (Democrats could win under a banner such as “Pick someone loyal to America.”)

Now, I leave open the possibility that Trump will be run out of office before 2020. (“Your tax returns or the presidency, Mr. President,” House Democrats might say if they get a subpoena for Trump’s documents enforced in federal court.) And I leave open the possibility that the Republicans would be so silly as to stick with a president who has tried at every turn to obstruct an investigation into his association with an enemy of the United States.

Nevertheless, that leaves us with a not insignificant chance that Democrats could have to run against someone other than Trump in 2020. What considerations come into play at that point?

For starters, Democrats would need to focus almost exclusively on their own, alternative vision for the United States. With Trump back in New York (or wherever), the question for voters would not be between Trump/Russian flunky and a possibly bland but mature Democratic figure; it would be a choice between whatever version of the GOP emerges from the wreckage of the Trump presidency and whatever vision the Democrats come up with. Democrats might be running against another right-wing populist, a pre-Trumpian Republican or a reformer Republican. Without a certain opponent, Democrats will need to put out a unifying, positive message that can stand on its own and unite their new coalition of young voters, nonwhites, women, suburbanites and college-educated voters.

Given the risk that they will be running against a sane, non-indictable Republican, Democrats had better make certain they don’t come up with a platform that plays only in the bluest locales. A candidate who is promising to enact Medicare-for-all, abolish Immigration and Customs Enforcement (ICE) and slash defense (and/or turn foreign policy into a matter of wealth inequality, as Sen. Elizabeth Warren (D-Mass.) did in a truly odd speech on Thursday) likely won’t win back the Rust Belt and the Upper Midwest, nor keep Western states such as Arizona and Nevada, which voted for Democrats for Senate in 2018, in Democrats’ column.

If Trump isn’t a factor, the concern about who will “stand up” to Trump fades, the rationale for, say, a Vice President Joe Biden or Michael Bloomberg candidacy dissipates, and the need for a fresh(er) voice becomes more urgent. You have to figure that Rep. Beto O’Rourke (D-Tex.), a can-do mayor or one of the new governors becomes a more attractive option. Like Jimmy Carter running in the wake of Watergate, a Democratic candidate who stresses values (honesty, decency, kindness, tolerance) and presents a compelling anti-corruption agenda might do very well. (It wouldn’t hurt to find someone from the heartland who has also won in rural areas.)

As my colleague Jonathan Capehart aptly put it, in a race against Trump, “Who cares if the eventual [Democratic] nominee only meets 80 percent — heck, 50.1 percent — of your checklist? Evicting Trump should be the most important item on that checklist.” A stable, unflappable and familiar candidate who promises to make America normal again might be all that Democrats need.

However, a race without Trump might require a candidate with very different qualities. Just as Democrats in 1976 found a relative unknown in an enormous field of big-name senators and governors — someone who promised not to lie to them and rejected the model of an “imperial president” — 2020 Democratic primary voters might look for someone who can definitively turn the page on the Trump era. Democrats should keep that in mind when pondering who should run and who can win in 2020.