MILWAUKEE — After weeks of personal sniping, the Republican presidential candidates clashed sharply over immigration and other policies at their debate here on Tuesday, with Gov. John Kasich of Ohio and former Gov. Jeb Bush of Florida trying to gain political momentum by heaping scorn on Donald Trump's plan to deport unauthorized immigrants.
In the most substantive Republican debate so far, Kasich and Bush, who have been fading in polls, presented themselves as experienced chief executives who had practical solutions to deal with national challenges like immigration. Yet both men, in expressing support for a comprehensive immigration overhaul, embraced a position that is unpopular with Republican primary voters, many of whom have responded enthusiastically to Trump's harsh rhetoric about immigrants who are in the country illegally.
While several other candidates, like Sen. Marco Rubio of Florida and retired neurosurgeon Ben Carson, received a pass from the moderators on immigration, Kasich took on the issue directly after Trump defended his plan to build a wall along the Mexican border and to identify and deport some 11 million people.
"Think about the families; think about the children," Kasich said. "Come on, folks, we know you can't pick them up and ship them across the border. It's a silly argument. It's not an adult argument."
Trump, whose counterpunches were a memorable part of his early debate performances, replied coolly at first, citing President Dwight D. Eisenhower's approach to deporting immigrants in the 1950s.
"You don't get nicer; you don't get friendlier," Trump said. "We have no choice. We have no choice."
But Kasich stayed on the attack against Trump. "Little false little things, sir, they really don't work when it comes to the truth," he said.
Bush then tried to pounce. He tweaked Trump, his longtime rival in the race, for suggesting that Bush be allowed to speak — "What a generous man you are" — and warned that Trump's harsh proposals would drive Hispanic voters to support the leading Democratic candidate, Hillary Rodham Clinton.
"They're doing high-fives in the Clinton campaign right now when they hear this," Bush said.
But policy details and disagreements, for the most part, replaced nasty potshots in the early going on Tuesday night.
Less than three months before Iowa begins the Republican nominating contest, the jostling in Milwaukee reflected the growing urgency the candidates feel to stand out in a sprawling 14-person field.
Some of the candidates expressed this frustration and sought to distinguish themselves by speaking more aggressively about their plans to cut taxes or create jobs — even if they did not deliver many specifics.
The debate offered a prime opportunity for the Republicans to distinguish themselves as economic thinkers with new ideas to create jobs or lower the national debt, $18 trillion and counting. But few of them left powerful impressions. Trump and Carson staked out their opposition to a $15 minimum wage but offered no new proposals to help poor and working-class people. Rubio agreed with them on the minimum wage but argued that higher education and vocational training must become more accessible and be aimed specifically at increasing wages.
Kentucky Sen. Rand Paul said he has several budget plans, all designed to shrink government spending. He seeks a 14.5 percent flat tax.
Paul says he wants a government that's "really, really small, so small you can barely see it."
Sensing an opening to appeal to the party's conservative grass roots after Kasich and Bush attacked Trump for his hard-line stance on immigration, Sen. Ted Cruz of Texas uncorked an assault on his own party and the news media.
Picking up on Bush's comment about Clinton's campaign exchanging "high-fives" over the Republican discussion about immigration, Cruz said Democrats were actually laughing. "If the Republicans join Democrats as the party of amnesty, we will lose," he said.
Businesswoman Carly Fiorina used a personal story to attack the president's health care law. She said that as a cancer survivor she knows better than anyone the importance of people with pre-existing conditions having access to health insurance.
She says the health care overhaul law championed by Obama "is failing the very people it's designed to help."
Undercard debate: Relegated to the Republican undercard debate for the first time, Chris Christie focused on attacking Democratic front-runner Hillary Rodham Clinton as he tried to use his performance as a springboard back into the field's top tier.
"Hillary Clinton's coming for your wallet everybody. Don't worry about Huckabee or Jindal, worry about her," he said early on in the hourlong debate.
"If you think Mike Huckabee won't be the kind of president who will cut back spending, or Chris Christie, or John Kasich, wait till you see what Hillary Clinton will do to this country," he added. "She will drown us in debt. She is the real adversary tonight."
The approach couldn't have been more different from that of an aggressive Bobby Jindal. The Louisiana governor jabbed at Christie and his fellow Republicans, criticizing their states' economic records.
The two sitting governors appeared with former Pennsylvania Sen. Rick Santorum and former Arkansas Gov. Mike Huckabee, who was also relegated from the prime-time debate to the earlier event.
Information from the Associated Press was used in this report.