MILWAUKEE --- The Republican presidential candidates turned serious here Tuesday night, largely setting aside personal attacks in favor of a spirited discussion on economic and other issues. In doing so, they highlighted the deep fault lines that are at the heart of the party's nomination battle.
One fault line underscored the frustrations of many grass-roots activists, who long for a nominee who espouses small-government conservatism without apology and who think they have lost the past two elections because their nominees were unable to do that.
The other fault line reflected the desire among conservatives for a tough stance against illegal immigration and the unease among Republicans that such policies will prevent the party from attracting more Hispanic votes and potentially doom them to defeat in 2016.
There were no clear winners, at least not so much as in the earlier debates, in part because there were strong moments for many of the candidates, as one after another grabbed for the spotlight.
It's not likely that what happened here on Tuesday will dramatically change the current shape of the race. But in highlighting the deeper differences in the party, the evening's discussions provided a helpful roadmap to the issues that will help determine the eventual nominee.
This was a night when it took both debates - one among eight candidates leading the polls and the other among four trailing candidates - for the tensions within the party to play out more clearly than in past encounters. And throughout the evening, the undercurrent that ran through many of the exchanges was the looming presence of Hillary Rodham Clinton, the current front-runner for the Democratic nomination.
The first debate featured sharp exchanges between New Jersey Gov. Chris Christie and Louisiana Gov. Bobby Jindal. Christie argued that the key to victory is his brand of conservative politics, which he said would give the party a better chance of defeating Clinton.
"I'll tell you what I'll bring to the table: the fact that I've won in a blue state, that I've won in a state that has 750,000 more Democrats than Republicans. . . . I won in a state for reelection after governing as a pro-life conservative and got 61 percent of the vote. That's the person you want on the stage prosecuting the case against Hillary Clinton."
Jindal argued strongly that sending a big-government conservative to Washington as president would lead to a perpetuation rather than a reversal of the policies that Republicans want to change. "Let's not be a second liberal party," Jindal said. "Let's actually cut government spending. Let's grow the American economy. Let's not just beat Hillary. Let's elect a conservative to the White House, not just any Republican."
The second debate broke open with a series of exchanges on immigration, with Donald Trump arguing that those who are here illegally should be sent back to their home countries before some are allowed to return. "We're a country of laws," he said. "We either have a country, or we don't have a country. They're going to have to go out."
That drew a swift rebuke from both Ohio Gov. John Kasich and former Florida governor Jeb Bush. Kasich said Trump was offering a "silly argument" by suggesting America would ever try to deport so many people. Bush said talk of deporting that many illegal immigrants was music to the ears of Democrats.
"They're doing high-fives in the Clinton campaign right now when they hear this," he said. "That's the problem with this. We have to win the presidency. And the way you win the presidency is to have practical plans."
Kasich was more forceful than he has been in past debates, seemingly determined not to be an afterthought at a time when he needs to move up. The same was true for Christie, who was relegated to the undercard debate when the number of candidates in the main debate was cut from 10 to eight.
Bush appeared more forceful at moments than in previous debates, a helpful change after what was widely judged a weak performance two weeks ago in Colorado. And despite some suggestions that the debate might feature another round of conflict with Sen. Marco Rubio, the two Floridians steered clear of one another.
Rubio offered another confident performance, deftly clipping pieces of his stump speech into effective answers on the economy and foreign policy. Sen. Ted Cruz of Texas, who like Rubio has been rising, was similarly effective in setting forth his conservative vision.
At one point, Rubio and Sen. Rand Paul of Kentucky went after one another on government spending. Paul upbraided Rubio for calling himself a conservative while advocating a substantial increase in defense spending. Rubio countered that in a dangerous world, more money for defense was a requirement, not an option.
Trump was Trump, occasionally insulting to some of his rivals but the most outspoken and firm on the issues of immigration.
Ben Carson, who came to the debate after days of controversy about his biography, was a calming presence but not a dominant one. He dealt with questions about his past by declaring that he doesn't mind being vetted but objects to what he sees as a double standard in which Democrats are not subjected to the same kind of scrutiny.
"People who know me know that I'm an honest person," he said.
Tuesday's debate came at a time when the Republican race was beginning to take on a three-tiered structure. Trump and Carson, the two outsiders, remained atop the national polls, as they have for many weeks. Rubio and Cruz make up the next tier, still well behind the two leaders but ahead of the rest of the crowded field.
But from here forward, the focus of the campaign increasingly will be on the state of play in the early states, particularly Iowa and New Hampshire. Trump and Carson continue to lead in both, but most of the other candidates are picking one of the two states - and their different electorates - to help propel them toward Super Tuesday and beyond.
The Wisconsin debate is the last among the Republicans for five weeks. If they hope to move the polls now, the candidates will have to rely on traditional methods: methodical retail campaigning in Iowa and New Hampshire with the goal of generating support by sometime in January; and television advertising that breaks through the daily clutter of media coverage.
What played out during the two debates here on Tuesday provided the frame by which voters in the primaries and caucuses will be asked to make their judgments. There is considerable agreement among Republicans about what they do not like about the policies of Clinton and President Obama. But before they get to that debate, they have issues of their own that the voters will be asked to resolve.
• 11/09/15: Trump v. Cason would be fun: Why let polls pick winners and losers?
• 10/29/15: Cruz and Rubio deliver breakout performances, but will Republican voters respond?
• 10/19/15: Is Bush's stock undervalued or a true measure of a troubled candidacy