As any bridge player can tell you, the game is different when there is no trump.

On Thursday night in Des Moines, Iowa, the seventh debate among major candidates for president in the Republican Party set a new standard in both substance and tone. And it did so because the front-runner in the 2016 nomination fight, Donald J. Trump, did not attend.

Gone were the outbursts and assertions from the charismatic billionaire who has upended the Republican nomination process. Gone were the personalized jibes and schoolyard taunts that have been a mainstay of earlier debates.

The seven candidates onstage seemed liberated, in varying degrees. There was also a sense that the electricity and the telegenic appeal of Trump's unpredictable and bombastic moments were both missing and missed.

That meant the central figure onstage was Texas Sen. Ted Cruz, who is running second to Trump in Iowa (where caucuses will be held Monday night) and contending with others for second in New Hampshire (where the primary is Feb. 9).

Cruz immediately tried to make a joke with pseudo-insults for everyone onstage: "Let me say, I'm a maniac and everyone on this stage is stupid, fat and ugly. And Ben, you're a terrible surgeon. Now that we've gotten the Donald Trump portion out of the way ..."

The joke drew a mixed response from the audience. Later, Cruz tried again, saying he'd quit the debate if he got "another mean question" from moderators who, he said, kept inviting his rivals to attack him. That, too, seemed to elicit catcalls as well as applause.

Both of these thrusts were meant to satirize Trump's boycott, which was at least initially cast as a rebuke to Fox News co-moderator Megyn Kelly. Trump has said Kelly is biased against him and is conducting a campaign against his candidacy.

As late as Thursday afternoon, Trump was exchanging phone calls with Roger Ailes, the legendary founder and head of Fox News, which co-sponsored the debate with Google. Ailes tried to persuade Trump to participate but refused to remove Kelly as co-moderator. Ailes said Trump offered to debate if Fox gave $5 million to Trump-backed charities — an offer Ailes said he refused.

So Trump held a rally across town at Drake University on Thursday night to raise money for veterans organizations, although he declined to say which ones. It drew an overflow crowd to an auditorium that seats about half as many as the 1,600 who crowded the hall for the Fox News and Google debate.

Trump not only remained the focal point for questions and responses in the debate, he also did well on social media, scoring more Google searches and mentions on Twitter and Facebook than the debate participants.

Nonetheless, he ran a risk in allowing a national television audience a chance to see the GOP field without his dominating media presence, which has rewritten all the manuals for conducting a White House campaign since entering the lists in early summer. Trump has built a formidable lead in national polls and in the states holding the early nominating events. He has done so while spending a fraction what his deep-pocketed intraparty opponents have spent.

Yet no one quite knows, with the first nominating event just three days away, what staying power Trump's legion of would-be kingmakers may have.

Front and center among the seven who did debate were Cruz and Florida Sen. Marco Rubio, who have been battling to be Trump's principal challenger. Cruz has had a distinct advantage in this regard in Iowa, where most of the Republican caucus participants identify as evangelicals. But Cruz has no comparable edge in the next two or three primary states, where he and Rubio are struggling not only with each other, but also with several other anti-establishment figures.

Fox challenged both Rubio and Cruz with sharply produced video montages showing them advocating earlier positions on immigration quite at odds with their current stances. Rubio was shown attacking the idea of a "path to citizenship" for any immigrants now in the U.S. illegally.

But this tack, taken in 2010, was repudiated by Rubio's support for a bipartisan compromise on immigration passed in the Senate in 2013 — a vote that Cruz has called a sellout to "amnesty." Cruz, for his part, was shown on videotape swearing his support for the bill Cruz helped fashion in the Senate in 2013.

Both men essentially denied the videos' implicit accusation of political hypocrisy. Rubio said he was just doing what he had to do in order to achieve progress on the issue, while Cruz said everyone knew where he stood on the issue of amnesty — whatever the tape seemed to show about a procedural maneuver he made in the past.

That prompted former Florida Gov. Jeb Bush to jump in, upbraiding Rubio, in particular, for acting as though his position had been unalterable. "He cut and run," he said, summing up how his onetime "protege" had abandoned the position the two once shared on a path to citizenship.

Overall, it was the best debate night to date for Bush. He seemed cheered and energized by the Trump-free environment, having what may have been his best debate of the campaign. He played down his dynastic credentials and government experience without disowning his father and brother, both of whom were president but left office under a cloud, having disappointed hard-core Republican voters in different ways.

Also clearly invigorated was Kentucky Sen. Rand Paul, who was back in the main debate line-up after failing to make the cut for the sixth debate. Both men had ample time to speak and differentiate themselves from the others onstage. Paul went after Cruz, in particular, for his posture as the steadfast conservative on every issue. Paul said Cruz had been on both sides of the amnesty question at one time or another, and: "He can't have it both ways ... it's a falsehood," he said, as cheers and objections were heard.

Chris Christie had another night of strongly worded speeches, most of them devoted to attacking Hillary Clinton for her actions or statements. Christie has played the aggressive federal prosecutor in previous debates, although with relatively little impact on the polls. On this night, he frequently shifted from the topic of the question to the topic of Hillary Clinton and the Democratic front-runner's legal exposures.

Also notable in the group of seven was the plucky and almost puppyish demeanor of Ohio Gov. John Kasich, who persists in detailing policy and administrative changes he has brought about in Columbus, harking back at times to his era in the Congress of the 1990s and early 2000s.

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