George Stephanopoulos used extremely poor judgment on Tuesday when he told a random New Yorker on 5th Avenue that he doesn’t think President Joe Biden can serve for four more years in the White House. It got him in trouble with his boss at ABC News who realizes that the incident has undermined Stephanopoulos’s reputation for objectivity. That’s ironic, because the Good Morning America anchor didn’t know he was being recorded and was only giving his honest assessment after having an exclusive sit-down with the president days earlier. It’s important to look at what Stephanopoulos was asked and how he answered.

The ‘GMA’ anchor was out and about Tuesday afternoon on 5th Avenue, wearing workout clothes, when the pedestrian approached him and asked, “Do you think Biden should step down? You’ve talked to him more than anybody else has lately.” George’s response — “I DON’T THINK HE CAN SERVE 4 MORE YEARS.”

He did not respond that Biden should step down because he cannot win. He did not say that Biden is incapable of making a forceful case for his own policies or a convincing case against Donald Trump’s record and proposals. Those are arguments you hear a lot of Democrats saying both publicly and privately, but they’re of secondary importance. Stephanopoulos has a background in Democratic politics, having served on Bill Clinton’s 1992 campaign and in his administration, but he didn’t make a partisan argument. He simply said that Biden, in his view, having talked to him “more than anybody else has lately,” is not capable of serving another four year term.

Could Stephanopoulos be wrong about that? Yes, he is not clairvoyant. But I give him credit for keeping the main thing the main thing. When it comes to whether Biden should run for another term in office, the most important thing is whether he can actually fulfill the job requirements. If the argument is that it’s not really that much of a concern because his vice-president can take over if needed, then his vice-president should be the candidate from the get-go. This is true on substance and merit, completely irrespective of the politics.

Here’s something obvious that still needs to be said. People suffering from cognitive difficulties can’t be relied upon to make good decisions. And that includes on when they should stop driving a car or living alone at home or step down and let their vice-president assume the responsibilities of the presidency. I’m willing to argue that we’re close to that point already, but it will only become more pronounced with each passing week and month because that’s how cognitive decline works…progressively and inexorably. We have to think about what might happen if Biden wins.

If Stephanopoulos is correct that Biden won’t be able to serve another full term, there will come a time when he should step down, but will he recognize that fact? Will he resist it and force a constitutional crisis?

And here is where we cannot avoid the political question anymore. How can we claim to be the responsible political party if we’re asking the American people to knowingly take this risk when it could be avoided? We can lie and say this isn’t the choice we’re imposing on the voting public, or we can pretend it’s a manageable problem even though it may not be manageable at all. Invoking the 25th Amendment to remove an incapacitated president is a messy and untested process that no one should risk, ever.

And so we can look at all the polls we want, and make all the comparisons to Trump’s cognitive condition that we want, and point to all the risks a second Trump presidency poses that we want, but if we don’t believe that Biden is a strong bet to finish a second term then we should not support him as the party’s nominee.

This really isn’t about Trump at all. The Republicans should not have nominated Trump and they should not support him. This is for a zillion reasons, including his own age and signs of cognitive decline. But that’s their decision and their responsibility. Simply put, the Democrats should not ask the public to vote for Biden in November because he’s clearly in cognitive decline. We can’t say that’s not true and we shouldn’t say it doesn’t matter.

There’s a strong feeling that Biden can’t win, but it’s possible that he could win. When you stay focused on what it would mean if he does win, it’s easier to see why he shouldn’t run.