Donald Trump looked like a fool and a fraud on Sunday. But what else is new?

Even the most ardent Trumpistas would have to admit that Trump’s appearance at the annual Rolling Thunder motorcycle rally was, as spectacles go, pretty pathetic. It was supposed to be a vast, multitudinous gathering on the plaza in front of the Lincoln Memorial, one of the greatest and most historic public spaces in the nation. Instead, Trump drew a paltry crowd estimated by organizers at perhaps 5,000.

As Trump might say in a late-night tweet: “Sad!”

The presumptive Republican nominee cut a ridiculous figure, sporting a red “Make America Great Again” baseball cap to guard against rogue breezes that might unhinge his comb-over. He lamented the attendance: “I thought this would be like Dr. Martin Luther King, where the people would be lined up from here all the way to the Washington Monument, right?”

Wrong. So very, very wrong.

Republican presidential candidate Donald Trump paid tribute to U.S. veterans on the steps of the Lincoln Memorial over the holiday weekend. (Reuters)

He claimed that the anticipated throng was out there, but “unfortunately, they don’t allow ’em to come in.” That was a lie; there were no hordes outside the security perimeter, pleading for admittance. Since everyone present could easily discern the truth, Trump must have been lying to himself — perhaps to ease the sting of what can only be seen as an awful week for his campaign.

As Trump showed the world, it is relatively easy to run for president if you are willing to say or do anything to get attention and you believe in nothing except your own self-inflated myth. His reality-television-style campaign overwhelmed a badly fractured Republican Party. But the act is getting harder to pull off because now his words, often chosen for their shock value, have real consequences.

Take his promise, made Thursday in a speech on energy policy, to cancel the Paris agreement on climate change and stop U.S. payments into a United Nations fund to mitigate the impact of global warming worldwide. That’s in keeping with Trump’s know-nothing approach to the climate issue, but it can hurt him more than he might imagine.

Trump apparently believes that he can defeat his likely opponent, Hillary Clinton, by winning the votes of some disaffected Democrats who support Sen. Bernie Sanders (I-Vt.). Yet while Trump has called climate change a “hoax” somehow perpetrated by the dastardly Chinese, Sanders calls it “the single greatest threat facing our planet” and proposes urgent and sweeping action to limit atmospheric and oceanic warming. Clinton basically agrees with Sanders, as evidenced by her unfortunately phrased promise to “put a lot of coal companies and coal miners out of business.”

Just like that, Sanders supporters for whom climate change is a paramount issue are out of Trump’s reach. It is hard to imagine how they could vote for a man who would renounce the landmark Paris deal, no matter what they think of Clinton.

Trump also spent the week fighting with New Mexico Gov. Susana Martinez, who happens to chair the Republican Governors Association and is considered one of the party’s brightest rising stars. Speaking in Albuquerque, he blamed Martinez for what he called the state’s lackluster economic performance. “It’s your governor’s fault,” he said. “She’s not doing the job.”

Martinez’s real transgressions, in Trump’s eyes, are that she has not endorsed him and didn’t attend his rally. He probably sees the feud as just another battle in his insurgency against the GOP establishment — but there’s one problem: Trump is the establishment now. He won the nomination, and with it comes leadership of the party. Perhaps Trump fancies himself a latter-day William Bligh, trying to maintain discipline on the HMS Bounty. But as we know, that did not end well.

1 of 10 Full Screen Autoplay Close Skip Ad × 10 celebrities who say they’ll leave the U.S. if Donald Trump is elected president View Photos From Jon Stewart to Cher, some said they’d move to Canada, but some preferred another planet. Caption From Jon Stewart to Cher, some said they’d move to Canada, but some preferred another planet. Jon Stewart After the Emmy Awards in September, Stewart was asked whether he’d consider returning to "The Daily Show" if Donald Trump is elected president in 2016. “I would consider getting in a rocket and going to another planet because clearly this planet has gone bonkers," he said. Chip Somodevilla/Getty Images Buy Photo Wait 1 second to continue.

Trump also spent time trying to resurrect two-decade-old conspiracy theories about the Clintons, explaining why he hadn’t given a promised $1 million to veterans organizations, calling Democratic Sen. Elizabeth Warren “Pocahontas” and saying she has a “big mouth” — a sign that Warren has gotten under Trump’s skin — and, oh yes, challenging Sanders to a debate and then chickening out.

By Sunday night, Trump was even losing on his favorite terrain. Weekly Standard editor Bill Kristol, a leading “Never Trump” conservative, announced on Twitter that “there will be an independent candidate — an impressive one, with a strong team and a real chance.” This prompted a frantic Trump tweet-storm about how Kristol was a “loser” and a “dummy” and how “lightweights” were setting up a “spoiler.”

When trolls get trolled: not a pretty sight.

Read more from Eugene Robinson’s archive, follow him on Twitter or subscribe to his updates on Facebook. You can also join him Tuesdays at 1 p.m. for a live Q&A.