( dpa ) - Democratic presidential hopefuls Barack Obama and Hillary Clinton sparred over meeting US enemies, immigration and leadership style in a debate Thursday night in Texas, the largest state contest left in the battle for the party's nomination.
Both candidates hammered home messages that have been at the heart of their campaigns, with Clinton highlighting her experience, preparedness and history of taking action, while Obama touted his sound judgement and ability to bring all sides together to achieve common goals.
But the exchange that will be replayed endlessly in coming days was over an accusation by Clinton that Obama had plagiarized portions of a speech from Massachusetts Governor Deval Patrick, as she used Obama's campaign slogan "change we can believe in" against him.
"If your candidacy is going to be about words, then they should be your own words," Clinton said. "Lifting whole passages from someone else's speeches is not change you can believe in. It's change you can Xerox."
Clinton's attack - which concerns language Obama used at a rally to highlight the power of words that was nearly identical to Patrick's own - drew boos from the crowd at the University of Texas in Austin.
Obama defended his use of Patrick's language, arguing that the Massachusetts governor is the co-chair of his campaign and had himself urged the Illinois senator to use the comments.
"The notion that I had plagiarized from one of my national co- chairs, who gave me the line and suggested that I use it, I think is silly," he said. "This is where we start getting into silly season in politics."
The exchange was an especially testy moment in an otherwise largely civil debate between the two senators, who have been locked since January in a tight race to become the Democratic nominee in the November 4 presidential election.
With Obama winning the last 11 contests since more than 20 states voted in the February 5 Super Tuesday events, Clinton is fighting to dent Obama's gathering momentum and has staked her campaign on winning primaries on March 4 in Texas and Ohio.
In a debate that spanned issues from the economy and health care to the Iraq war, the two candidates drew some of their sharpest distinctions over the presidential role in foreign policy.
Following the resignation of ailing Fidel Castro in Cuba earlier this week, the two disagreed over whether to meet with his brother and heir-apparent, Raul Castro, as the US hopes to nudge the communist island toward democracy.
Clinton said she would meet Castro only after seeing "evidence" of Democratic reforms and charged that immediate meetings with adversaries would "undermine" the office of the president.
"I would get back to very vigorous diplomacy. I want to send a very clear message to the rest of the world that the era of unilateralism, pre-emption and arrogance of the Bush administration is over," she said, drawing loud cheers from the crowd.
Obama said he would meet Raul Castro "without preconditions" in order to press him to restore human rights and democracy, repeating a pledge he has made to meet with all US adversaries.
"If we think that meeting with the president is a privilege that has to be earned, I think that reinforces the sense that we stand above the rest of the world," he said. "It's important for us, in undoing the damage that has been done over the last seven years, for the president to be willing to take that extra step."
The debate was hosted by broadcaster CNN and the largest US-based Spanish-language television station, Univision, in a state that borders Mexico and has a large Hispanic minority.
The issue of illegal immigration and securing the US border took on a central role as both candidates promised to work for a comprehensive solution that has failed to pass through Congress twice in the last three years.
Obama said that the contentious debate has caused a spike in hate crimes against Hispanics and called on all sides to "tone down the rhetoric," while Clinton said she would listen to those people living along the border region and bring a reform bill to Congress within the first 100 days of taking office.