By Greg Giroux, CQ Staff

There have been so many presidential candidate debates that even the most zealous political junkies have lost count by now. But Thursday’s Democratic debate between Sens. Hillary Rodham Clinton and Barack Obama was the most eagerly anticipated encounter of them all.

That’s because the debate, which was held in Austin, Texas, and broadcast on CNN and later on Univision, was the first joint appearance between Clinton and Obama in three weeks — an eternity in a Democratic contest that has included many unexpected twists and turns.

The debate was expected to have a much more combative tone than the last Clinton-Obama joint encounter — a civil affair on Jan. 31 that was held just before “Super Tuesday” on Feb. 5 that produced no clear front-runner for the Democratic nomination. Since then, Obama has amassed a double-digit winning streak of state primaries and caucuses that has seriously wounded the Clinton campaign, which needs to stanch Obama’s momentum ahead of critical primaries in Ohio and Texas on March 4 (Vermont and Rhode Island also will hold primaries on that day).

But it took a long time for Thursday’s debate to flesh out any points of disagreement between Clinton and Obama, who spent more time attacking President Bush and his policies than each other. They found common ground on a number of issues. In the first half of the 90-minute debate, in fact, Clinton and Obama didn’t criticize each other.

It wasn’t for lack of trying on CNN’s John King’s part. Early in the debate, he asked Clinton and Obama to contrast their approaches for managing the economy as president. Neither candidate took the bait. They denounced the Bush administration’s tax proposals and also agreed on immigration policy.

The second half of the debate yielded some disagreements and barbs. Clinton said that she was “amused” that an Obama surrogate — Texas state Sen. Kirk Watson, who represents Austin — couldn’t name a single legislative accomplishment by Obama when pressed by MSNBC broadcaster Chris Matthews during an interview this week. Obama, for his part, noted his work on health care and criminal justice issues and his prominent role in the Senate to overhaul ethics laws.

The following are CQ Politics’ Mosts and Bests from Thursday evening’s debate:

• Most Discussed Issue: Probably a tie between health care and immigration — both big concerns in a border state that includes many impoverished regions where individuals don’t have health insurance or struggle to pay for it.

Health care didn’t get mentioned in the first half of the debate, but occupied a good chunk of its second half. The biggest difference in the candidates’ health care plans is that Clinton’s universal coverage plan includes a mandate requiring everyone to purchase health insurance and Obama’s does not.

“This is a significant difference,” Clinton said. “Sen. Obama has said it’s a philosophical difference; I think it’s a substantive difference. ... I just know that if we don’t go and require everyone to have health insurance, the health insurance industry will still game the system.”

Obama said that people who lack health insurance want it but can’t afford it, and that an all-encompassing mandate would result in fines on people who can’t afford coverage. Obama says his plan would reduce health care premiums by $2,500 per family per year. “Both of us seek to get universal health care. I have a substantive difference with Sen. Clinton on how to get there,” Obama said.

Obama also said he would overhaul health care as president in a more transparent manner than the Clinton Administration did 15 years ago, when Sen. Clinton was a chief architect of a sweeping health care proposal that failed.

The candidates see eye-to-eye on immigration policy, though. Both Clinton and Obama expressed support for an overhaul of immigration laws that would include a “path to citizenship” for many illegal entrants.

• Most Predictable Statements: Both candidates reiterated the major themes that have punctuated their campaigns of late. Clinton said that she was prepared to serve as president on “day one,” while Obama said he was well-equipped to bring about needed change in Washington, D.C., where he said that “too many politicians are interested in scoring political points rather than bridging differences in order to get things done.”

• Biggest Zinger: “Lifting whole passages from someone else’s speeches is not change you can believe in; it’s change you can Xerox.” Clinton delivered this memorable line after Obama responded to a question about recent revelations that recent speeches included some phrases that were delivered by Massachusetts Gov. Deval Patrick , a prominent Obama supporter, when Patrick was running for governor in 2006.

Speaking before Clinton, Obama said that the accusations of plagiarism were “silly” and indicative of a “silly season” in the current campaign — and that the debate should turn to substantive issues.

“I’m happy to have a debate on the issues. But what we shouldn’t be spending time doing is tearing each other down — we should be spending time lifting the country up,” Obama said.

• Most Timely Issue: Cuba. The recent news that longtime Cuban leader Fidel Castro will relinquish power spawned the debate’s first question: would the candidates be willing to meet with Raul Castro, Fidel Castro’s brother, who is expected to become the nation’s next president?

Clinton said she would not meet with Raul Castro until Cuba has taken proactive steps such as opening up its economy, releasing political prisoners and ending oppressive practices on the press.

“Of course the U.S. stands ready, and as president, I would be ready to reach out and work with a new Cuban government once it demonstrated that it truly was going to change that direction,” Clinton said. She added: “A presidential visit should not be offered and given without some evidence that it will demonstrate the kind of progress that is in our interest and, in this case, in the interest of the Cuban people.”

Obama said that he would meet with the new Cuban leadership, but that a “starting point” to U.S. policy in Cuba should be “the liberty of the Cuban people.”

“I would meet without preconditions, although Sen. Clinton is right that there has to be preparation,” Obama said. “It is very important of us to make sure there was an agenda, and on that agenda was human rights, releasing of political prisoners, opening up the press. ... But I do think that it’s important for the United States not just to talk to its friends, but also to talk to its enemies.”

• Biggest Back-burner Issue: Iraq didn’t get a whole lot of attention in the debate, though the two candidates had covered this ground in previous encounters. Obama opposed the Iraq War from the very start and supports a timeline to begin withdrawing U.S. troops from Iraq. Clinton voted for the original 2002 resolution that authorized President Bush to wage military operations in Iraq, but promises to begin withdrawing U.S. troops from Iraq early in her administration.

• Most Original Question: In the debate’s final question, CNN’s Campbell Brown asked each candidate to describe a “moment of crisis” in their lives when they were “tested” the most.

Obama, who was raised by his mother and grandparents and worked as a community organizer, said that the “cumulative experience” in his life instilled in him good judgment and an ability to bring people together. “What was most important in my life was learning to take responsibility for my own actions — learning to take responsibility for not only my own actions, but how I can bring people together to actually have an impact on the world,” Obama said.

Clinton said that she faced challenges in her life as well, but that her problems paled in comparison to “what I see in the lives of Americans every single day.” She segued to an anecdote about wounded war veterans she met at a medical center in San Antonio.

• Most Unifying Moment: When Obama and Clinton shook hands near the end of the debate, after Clinton, in a moving finale, said that she was “absolutely honored” to appear with Obama.

“Whatever happens, we’re going to be fine,” Clinton said. “We have strong support from our families and our friends. I just hope we’ll be able to say the same thing about the American people, and that’s what this election should be about.”