Republican presidential candidate Jeb Bush is polling at 3 percent. (Chuck Burton/AP)

Watching the Republican presidential debate Thursday night, I kept trying to figure out how to grade Jeb Bush’s performance.

He clearly wasn’t winning the debate, because he was largely a bystander in the dominant fight between Donald Trump and Sen. Ted Cruz (Tex.). But Bush also wasn’t losing: He made serious and nuanced points about immigration and foreign policy, and he demonstrated deep knowledge about almost every issue.

Then I realized what it was I was feeling about Bush: I just felt bad for him.

You feel bad for a two-term governor of Florida and the scion of the first family of Republican politics, you ask? That’s either (a) stupid or (b) condescending. (Who the heck am I to feel bad for him, after all?)

Be that as it may, it’s how I felt. And it’s how I’ve felt about Bush for much of this campaign.

At a campaign event in Hilton Head, S.C., Republican front-runner Donald Trump criticized Jeb Bush for overspending on political advertisements and low poll numbers. (Reuters)

I’m not alone. Just look at how Bush was portrayed on “Saturday Night Live” over the weekend. In a skit re-creating Thursday’s debate, he was cast as the bullied kid — Trump calls him “Jebrah” and smashes Bush’s hand into his face. Then, when given the opportunity to tell a “joke,” Bush bombs.

Or put aside satire and look at what voters are saying about him. “It looks like he needs someone to walk up from behind him and give him a little nudge,” Pennsylvanian Janet DeHart told The Washington Post’s Ed O’Keefe for a recent article headlined “Why do so many Republicans dislike Jeb Bush?” Side note: She is 81.

Look at the course of his campaign. He entered the race in the spring as the clear front-runner — a status conferred upon him by his last name, his expected financial juggernaut and the depth of his résumé.

Butit became clear early on that Bush wasn’t just rusty at this campaigning thing, he simply wasn’t all that good at it. It also was obvious to anyone paying attention that Bush was badly miscast in an election cycle in which the Republican base wanted anger from its candidates. Bush does pragmatic leadership, not anger. And when he does get angry, it’s the golly-gee-willikers kind of mad, not the I-am-going-to-punch-someone-in-the-face type.

The rise of Trump — and his relentless attacks on Bush as a “low-energy person” — only served to highlight the disconnect between Bush and his party’s base. “What did Donald say? He’s ‘low-energy.’ It’s exactly right,” DeHart told O’Keefe.

On Thursday night, as he has throughout the campaign, Bush painted a picture of a complex world — from the Middle East to here at home. His answers to questions were larded with detail and complexity. On Trump’s call to ban Muslims from entering the country, for example, he was measured and thoughtful. “Every time we send signals like this, we send a signal of weakness, not strength,” Bush said.

For almost every one of those answers, the crowd, which was not pro-Trump by any means, greeted Bush’s response with polite applause. You could almost imagine audience members leaning over to their friends and saying, “Jeb’s so nice. And so smart.” Of course, they also almost certainly won’t vote for him.

I think, at some level, Bush understands the ridiculousness of his situation. You could see it written all over his face Thursday night — especially when he and Trump were going back and forth over the latter’s call for a ban on Muslims. You can almost see him thinking “You guys are really taking this all seriously?” every time Trump talks.

Bush is in a race with someone who refuses to play by any of the established rules or even acknowledge that there are rules. For a rule-follower such as Bush, Trump’s flouting of how-things-are-supposed-to-work is mind-blowing — and impossible to counter.

Bush knows the world is complex. He knows that problems aren’t solved simply because you say so. He knows the work of governance is hard.

And yet and yet and yet. Bush, as Trump likes to remind him, is at 3 percent while Trump is at 33 percent.

So, yes, I feel bad for him. He’s hopelessly miscast in this race, and, worst of all, he knows it.