Washington ? Don’t be sure the McCain episode is the beginning of the end of Donald Trump’s bizarre presidential campaign. Don’t even be sure it’s the end of the beginning. Attacking him with censure and shame is like trying to destroy Godzilla with electricity: It might just make him stronger.

Why should anyone pay the slightest attention to the Trump circus? Because the most recent polls — to the GOP establishment’s great consternation — show him in first place. Also because Trump, rather than any of his more experienced rivals, is setting the agenda for the race.

On Saturday, he committed what for most politicians would be a fatal gaffe. Speaking extemporaneously at a candidates’ forum in Iowa, Trump turned his rhetorical blunderbuss toward Sen. John McCain, R-Ariz., who had accused Trump of using outrageous statements about illegal immigration to incite the “crazies” in the GOP base.

“He’s not a war hero,” Trump said of McCain. “He’s a war hero because he was captured. I like people that weren’t captured.” Trump also derided McCain’s academic record at the U.S. Naval Academy and his record as a senator.

It says something about our politics that denigrating McCain’s war record was seen as more transgressive than claiming the government of Mexico is deliberately sending hordes of rapists and other criminals across the border into the United States. McCain served in Vietnam as a Navy pilot; he was shot down and endured years of torture and abuse as a prisoner of war.

Rick Perry said it was “a new low in American politics.” Jeb Bush accused Trump of “slanderous attacks” against McCain. Lindsey Graham said Trump’s remarks were “stupid” and disqualified him as commander in chief. Scott Walker, Rick Santorum and Bobby Jindal also chimed in with outraged opprobrium — although Ted Cruz, who has gone out of his way to be nice to Trump, confined himself to calling McCain a war hero and “a friend of mine,” which might be news to McCain.

Republican National Committee strategist Sean Spicer said on Twitter that there is “no place in our party or our country for comments that disparage those who have served honorably.” The only remotely witty response came from Mitt Romney, who tweeted that the difference between McCain and Trump is that “Trump shot himself down.”

Well, maybe. My guess is that those who speak of Trump in the past tense are guilty of wishful thinking.

There are two things about Trump that politicians find nearly impossible to understand: He has nothing to lose. And as long as people talk about him, he doesn’t care what they say.

Go ahead, chatter away about how Trump clamored for a series of student draft deferments while McCain languished in a North Vietnamese prison camp. Draw all the contrast you want between the injured pilot who subsisted on gruel and the New York playboy who frequented the city’s best restaurants and flashiest night clubs. See if Trump cares.

Rather than exhibit remorse or shame — concepts he might not understand — Trump bulled ahead in his criticism of McCain’s record.

“The reality is that John McCain the politician has made America less safe, sent our brave soldiers into wrongheaded foreign adventures, covered up for President Obama with the VA scandal and has spent most of his time in the Senate pushing amnesty,” Trump declared Monday in a USA Today op-ed. “A number of my competitors for the Republican nomination have no business running for president. I do not need to be lectured by any of them.”

Oh, but he does need to be the center of attention, whether he’s being lectured, hectored, raked over the coals or praised to the heavens. And for yet another week, the GOP campaign is about him, not about anyone else. In Trump’s world, that’s called winning.

I’m not sure that Republican grandees understand the nature of Trump’s appeal, which is that he defies the traditional customs and strictures of politics. He doesn’t censor himself. He doesn’t apologize. When somebody hits him, he hits back.

Even if the McCain flap were to cost Trump fully half of his support, which I think is highly unlikely, he’d still be a top-tier candidate. The GOP isn’t free of him yet. Godzilla is still on the loose.

— Eugene Robinson is a columnist for Washington Post Writers Group