LAS VEGAS — Images speak loudly in politics, and a day before the Nevada caucuses, Mitt Romney, accompanied by his new Secret Service detail, seemed to be auditioning for the White House, aiming all his criticism at its current occupant.

Newt Gingrich, meanwhile, continued to cast himself as the insurgent spoiler, holding a rally Friday in a cowboy bar with a mechanical bull, as he blazed away from all angles at Romney, the perceived Republican front-runner.

The momentum Romney picked up after his resounding victory in the Florida primary shows no signs of waning through the many contests this month in Western states, where Romney finished strongly in 2008. Many states, like Nevada, have significant Mormon populations and conservative voters, especially in Arizona, who like his hawkish views on illegal immigration.

With polls showing a double-digit lead over Gingrich, Romney confidently met with business leaders in northern Nevada. He never mentioned his rival, turning his focus to President Barack Obama. “If I become president of the United States, I commit to be a friend of working people and employers and entrepreneurs and innovators,” he said.

He greeted the big economic story of the day — that unemployment had fallen to 8.3 percent, a three-year low — as “good news,” but he did not let up on Obama.

“I know the president didn’t cause this downturn, this recession,” he said, “but he didn’t make it better either. He made it worse.”

It was a dubious statement, because the unemployment rate fell to precisely what it was during Obama’s first full month in office, February 2009, and nonideological economists agree that the stimulus actions taken by the administration and the Federal Reserve kept the recession from being worse.

Romney did not return to a remark earlier in the week that he was “not concerned about the very poor” because they would be helped by a safety net of government programs. He had already walked back the phrase, saying that he “misspoke.” But Gingrich, hoping for a second-place finish in the caucuses to pick up delegates to the Republican convention — a result by no means assured given the superior organizing effort of Rep. Ron Paul of Texas — was not done with the “very poor” issue.

He equated Romney’s attitude with the worldview of Obama, contrasting it with his own “genuine conservative” position, namely that what the poor really need from government are pro-growth, pro-job policies.

“We think it is the left which has abandoned and betrayed the poor, because its safety net is actually a spider web, and it traps people in dependency,” Gingrich said during a rally at Stoney’s Rockin’ Country bar in Las Vegas. “My goal is the exact opposite of Gov. Romney’s. My goal is to turn the safety net into a trampoline to allow the poor to rise and be like the rest of us.”

Gingrich updated one of his signature attacks on Obama — that he is a “food-stamp president” — to include Romney. The president, he said, is “big food stamp” and Romney is “little food stamp.”

And he added to the theme that Romney is a moderate, closer to the president than what the conservative base of the Republican Party wants. He described a new video his campaign released Friday that uses recent comments by George Soros that “there isn’t all that much difference” between Obama and Romney.

“It isn’t good enough for the Republican Party to nominate Obama Light,” Gingrich said.