Last week’s race-watching news was dominated by Jeb Bush’s spectacular three-day shambles of an answer to Megyn Kelly’s question about Iraq: “Knowing what we know now, would you have authorized the invasion?”

What was amazing about this question was how difficult it was for him to answer. First he misheard it — “I would have, and so would have Hillary Clinton, just to remind everybody. And so would have almost everybody that was confronted with the intelligence they got.”

But then, Thursday, after some intervening flubs, he admitted: “Knowing what we know now, I would not have engaged. I would not have gone into Iraq.”

The thing about hypothetical counterfactuals that start with “knowing what we know now” is — these questions are not difficult. It is not hard to give people the answer they want to hear. You are playing the game in Hindsight Mode, which is the easiest mode possible, even easier than the Demo mode, where you watch over a shoulder while someone in your immediate family plays through the whole thing first. You have a magical power of vision that cliche-ridden writers describe as being “20/20.” The fact that it took Bush days to realize this does not bode superbly well. Imagine asking him a hypothetical question where there wasn’t one answer generally viewed as correct.

But just in case we thought that fumbling and dropping your response to this question butter-side down on the carpet was the exclusive purview of people who did not wish to embarrass their president brothers, Marco Rubio did a pretty splendid job of bumbling it on Sunday, telling Chris Wallace that “It was not a mistake. The president, based on — this is the way the real world works. The president, based on the information that was provided to him…. Well, based on what we know now, a lot of things — based on what we know now, I wouldn’t have, you know, thought Manny Pacquiao was going to beat in — in that fight a couple of weeks ago.”

Wallace continued to press: “So, was it a mistake or not?”

He received the illuminating answer, “But I wouldn’t characterize it — but I don’t understand the question you’re asking, because the president –”
“I’m asking you,” Wallace went on, “knowing, as we sit here in 2015 –”
“No, but that’s not the way presidents — a president cannot make decision on what someone might know in the future.”

No. But a candidate certainly can answer questions based on that.

This is not hard to get right. We know now what we know now. The decision might be difficult, but answering a question like this should not be. This is a yes or no question. Imagine if they’d asked something in essay format, like, “In this situation, what would you have done differently?” They’d have been stymied for days, and Rubio would probably have started talking about the “Mad Men” finale again.

Just to review: It is only a silly question until you get it wrong.