ANALYSIS: Sharp Policy Divisions Emerge in GOP Debate

The stage was smaller. The rhetoric was milder. But the broad contours of the presidential race were somehow brought into sharper relief by an evening that was often dull.Talk of immigration, foreign policy and bank bailouts was a throwback for a Republican Party that's been rocked by sideshows, surprises, and campaign drama. As comfort zones go, though, this was awkward territory for a GOP that's seeking its own identity while reaching out to a changing electorate.Donald Trump was the center of some of the most important action of the night, in a reminder that he doesn't have to be loud or insulting to influence a presidential debate.His argument for building a border wall and forcing undocumented immigrants out of the country sparked a debate where the moderators weren't even looking for one."We either have a country or we don't have a country," Trump said of the need to "send people out" who came to the US illegally.His vision for the country, of course, is not unanimous inside his party. It earned Trump a Jeb Bush-John Kasich tag team -- in a series of exchanges that will resonate throughout the primary season."Think about the families. Think about the children," Kasich said. "For the 11 million people, come on folks, we all know you can't pick them up and ship them back across the border."Trump got so flustered with Kasich that he asked that Bush be allowed to answer. (Later, he'd get booed for complaining that Carly Fiorina was interrupting to talk foreign policy.)The Best Lines From the GOP DebateBen Carson Says He Has 'No Problem' Being Vetted After Questions About His PastBush used the exchange to get some of his campaign groove back, delivering a reminder of why he's often said he's running."It's just not possible. And it's just not embracing American values," Bush said of Trump's plans. "We have to win the presidency, and the way you win the presidency is to have practical plans."Marco Rubio, playing a different game that doesn't involve talking much about immigration where he can, chose not to engage.But Ted Cruz -- who, like Rubio, wasn't even asked about immigration -- jumped in."If Republicans join Democrats as the party of amnesty, we will lose," Cruz said.Rubio reserved his fire for Rand Paul, whose questioning of GOP foreign policy dogma of the last generation left him lonely, yet speaking to a not insignificant portion of voters."I know that Rand is a committed isolationist. I'm not," Rubio said."How is it conservative to add a trillion dollars in military expenditures?" Paul shot back.Added Cruz: "You think defending this nation is expensive, try not defending it."And Bush took on Trump after he said he was glad the Russians were taking a leading role in fighting ISIS in Syria."We're not going to be the world's policeman. But we sure as heck better be the world's leader," Bush said.Ben Carson spent a second straight debate in a prime position yet barely being forced to engage his rivals. The candidates at one point argued over who has gotten to know Vladimir Putin best, so they could hate him the most; Cruz and Rubio had small, uncharacteristic flubs; Trump looked more flustered than he has in the past.Cruz and Rubio did find moments to break through, in a debate that didn't shake things up so much as it seemed to confirm the status quo of a volatile race. Republicans found agreement, of course, in saying Hillary Clinton represents the past."The Democratic Party and the political left have no ideas about the future," Rubio said. "This nation is going to turn the page."Rubio and his rivals, though, made clear that the next chapter is still being written -- and is likely to be a messy one.Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download ABC News for iPhone here or ABC News for Android here.