(JIM WATSON/AFP)
Opinion writer

The winner of Thursday’s Republican debate was. . .Jeb Bush?

This is the first time in the GOP presidential race in which the candidate who was the most credible on the issues also won the debate. Maybe Donald Trump’s absence gave Bush a confidence boost — or at least permitted him to get a word in edgewise. Perhaps Bush, with little to lose at this point, relaxed. Or maybe he is just more polished after months of campaigning. Whatever the reason, he spoke with more conviction and dominated the stage at several points in the debate. And he used some of those moments to bring policy specifics and high principles into an otherwise dismal conversation.

While the other candidates pretended that pumping up the military, ranting about “radical Islamic terror” and ordering saturation bombing is a strategy to defeat the Islamic State, Bush called for pumping up the military — but also establishing a no-fly zone, creating safe zones for refugees and training a Sunni ground force to retake territory. (In truth this is roughly what Hillary Clinton wants to do, but no one pointed that out, so it was safe to propose.)

Bush once again bucked the other candidates’ disgusting embrace of Trumpism, arguing for offering illegal immigrants a path to legalization. But he may have turned that into a tactical as well as moral victory as he and the moderators pointed out that Marco Rubio and others on stage supported a pathway to legalization, too — or at least had before running for president. Rubio, he said, “cut and run” when the politics got hard. Rubio looked like a crypto-amnesty supporter and a coward. For once Bush won a one-on-one on-stage debate faceoff.

Moreover, Bush argued that conservatism is not about protecting the nation from or for any particular ethnic group or religion. Quite the opposite: “We should be a welcoming nation. Our identity is not based on race or ethnicity, it’s based on a set of shared values. That’s American citizenship,” he said. “You can deal with the threat of terror and also recognize that this country should be aspirational.” This was the one debate in the GOP campaign so far in which these obvious points did not seem doomed to be crushed by the unrelenting anger, fear-mongering and nastiness of the other candidates.

Bush’s performance may not be enough to rescue his flailing candidacy. But he showed that one can put in a strong showing in a GOP debate without being a bile-spouting rage machine, and he may peel off some people who are attracted to the other candidates’ confidence rather than their specific, objectionable policies.

And everyone else? Ted Cruz started off well. “Let me say, I’m a maniac and everyone on this stage is stupid, fat, and ugly. And, Ben, you’re a terrible surgeon,” he said. “Now that we’ve gotten the Donald Trump portion out of the way…” But his other prepared lines fell flat. (“Gosh, if you guys ask one more mean question I may have to leave the stage.”) Over the course of the night he seemed increasingly smug, talking over Fox News’s Chris Wallace and once again attempting to gain sympathy by digging into the moderators. Meanwhile, others on stage attacked him for being insufferably holier-than-thou, which is how pretty much all of his Senate colleagues seem to feel about him.

Rubio won the award for being nastiest to President Obama. But he lost big on immigration. Even though the debate was in Iowa, John Kasich did not even pretend he was campaigning anywhere except New Hampshire, awkwardly bringing up the endorsements he has gotten in the Granite State. Chris Christie argued that he would keep the country safe and mentioned his proximity to 9/11, which is to say he did little different from past debates. And Trump, you may have heard, was not there.

In other words, the only one who had a halfway decent night was Bush. And he actually deserved it.