By Rachel Kapochunas, CQ Staff

The following are CQ Politics’ selected highlights of the Democratic presidential candidates’ debate Thursday night, which was held at the University of Nevada at Las Vegas and televised on CNN. It was moderated by CNN anchorman Wolf Blitzer, with network correspondents Campbell Brown, John Roberts and Suzanne Malveaux also participating in questioning the candidates.

The debate was held in one of the four states permitted under national Democratic Party rules to hold presidential nominating contests prior to Feb. 5, 2008. Nevada’s caucuses are scheduled for Jan. 19.

• Most discussed topic: Foreign policy. The candidates answered questions not only on Iraq and the ongoing war there, but on Pakistan, where President Pervez Musharraf has declared a state of emergency; on their views about the possibility of armed conflict with Iran; and on trade relations with China.

Several candidates used the foreign policy questions as an opportunity to brandish their credentials. In a oblique criticism of President Bush, Delaware Sen. Joseph R. Biden Jr. — who chairs the Senate Foreign Relations Committee — mentioned that he spoke to leaders in Pakistan about that nation’s current crisis “before the president” did. New Mexico Gov. Bill Richardson noted his history in international diplomacy, including his experience as U.S. ambassador to the United Nations under President Bill Clinton from 1997 to 1998.

• Most combative exchanges among candidates: New York Sen. Hillary Rodham Clinton and Illinois Sen. Barack Obama , the front-runner and runner-up in Democratic presidential preference polls, opened the debate with a heated exchange in which each candidate took several turns to blast the other. Obama kicked it off by suggesting Clinton is not someone who gives “straight answers to tough questions,” citing what critics said was an indirect answer in the last Democratic debate on whether she would support issuing drivers’ licenses to illegal immigrants.

The exchange turned to health care, with Obama accusing Clinton of believing that the only problem facing the uninsured is that there are no mandates to require them to have health care. He then mentioned that his plan will cover all Americans. “I cannot let that go unanswered,” Clinton interrupted and was given time to argue that Obama’s proposed plan “does not cover everyone.”

In the second half of the debate, Obama accused Clinton of misconstruing his views by saying that his support for increasing the income cap on Social Security taxes — what she has called a “trillion-dollar tax increase” — would be a hardship for middle-class individuals. Defending the proposal as one that would mainly affect higher-income taxpayers, not the middle class, Obama chastised Clinton by lumping her in with two leading candidates for the Republican presidential nomination. “This is the kind of thing I would expect from Mitt Romney or Rudy Giuliani ,” Obama said, referring respectively to the former governor of Massachusetts and the former mayor of New York City.

• Most time on defense: Clinton spent the most time defending her past statements and positions. She was asked to clarify her views on drivers’ licenses for illegal immigrants, answer allusions that she is too “polarizing” to be successful, and defend her changes of position on certain issues.

• Best Table-Turning Response. Clinton also was called upon to respond to criticisms that she is playing the “gender card” in her bid to become the nation’s first woman president.

“I’m not exploiting anything at all,” Clinton said. Noting that the debate was in Las Vegas — which happens to be famous as a haven for legal gambling — she said, “I’m not playing, as some people say, ‘the gender card.’ I’m just playing the winning card.”

“They’re not attacking me because I’m a woman. They’re attacking me because I’m ahead,” she concluded to applause from some in the audience.

• Most criticized question from the moderator: Blitzer demanded that each candidate provide a “yes” or “no” answer on whether they support providing drivers’ licenses to illegal immigrants in the absence of immigration reform — a politically volatile issue that caused particular problems for Clinton in the most recent previous debate, when she appeared to hedge about her views. Nearly all the candidates rebuked Blitzer for seeking a simplistic answer to a complicated issue, with some saying it had to be considered within the context of the overall question of what to do about illegal immigration.

Blitzer’s effort to frame the driver’s license issue as one that should be considered separately because a more sweeping immigration policy was not going to be enacted only served to inflame the negative responses from some of the candidates. “I don’t accept the proposition that we will not have comprehensive immigration reform,” said John Edwards , the former North Carolina senator who was the 2004 Democratic vice presidential nominee.

Clinton and Biden, though, did not take issue with the format. Each answered the question of whether they supported driver’s licenses for undocumented immigrants with the single word: “No.”

• Best self-introduction: Richardson, the only Western candidate on the stage, has trailed deeply in the polls and needs to do very well in the early Nevada caucuses if he hopes to leap forward into the top tier of candidates. But nearly 20 minutes at the outset of the debate were dominated by exchanges among Clinton, Obama and Edwards, something of which Richardson sardonically took note when he finally was given his first opportunity to speak.

“By the way, I’m Bill Richardson , the governor of New Mexico,” he began, which was met by laughter from the audience.

• Most sweeping insult (but just kidding!): “Hell, no. I wouldn’t support any of these guys,” Biden responded in jest when asked if he would support the party nominee, regardless of who that turns out to be. The question was prompted by a recent remark by Edwards that appeared to suggest that he was not committed to backing Clinton should she win the nomination, though Edwards joined five other contenders at the debate who said unconditionally that they will endorse the nominee. Ohio Rep. Dennis J. Kucinich , a staunch opponent of the Iraq War, gave the only nuanced response to the question, saying his decision about whether to endorse would depend on the winning candidate’s stance on the war.

• Top One-Upmanship: Blitzer noted that Kucinich was the only candidate on the stage who voted against the Patriot Act, which expanded domestic intelligence-gathering in the wake of the Sept. 11 terrorist attacks but contains provisions that critics say abridge civil liberties. Kucinich responded: “That’s because I read it.”