Hillary Clinton and Bernie Sanders tangled in their first one-on-one debate over how to achieve liberal goals such as health care for all and a better education system.
Clinton last night dismissed Sanders' proposals as "just not achievable," while Sanders countered that Clinton was willing to settle for less than Americans deserve.
"I do not accept the belief that the United States of America can't do that," Sanders said of his plan for universal health care and of his efforts to take on "the rip-offs of the pharmaceutical industry."
Clinton insisted they both want the same thing, "the disagreement is where do we start from and where do we end up."
The race for the Democratic nomination, once seen as a sure thing for Clinton, intensified this week after Sanders held the former secretary of state to a whisper-thin margin of victory in Iowa's leadoff caucuses.
The tone of their back-and-forth has become increasingly sharp, and the candidates agreed to add four more debates to the primary season schedule.
The debate is the last before Tuesday's first-in-the-nation New Hampshire primary, and Sanders holds a big lead in polls in the state.
In fresh evidence of the tightening race, Clinton reported that her campaign had raised USD 15 million in January -- USD 5 million less than Sanders and the first time she's been outraised by her opponent.
Her finance director called the numbers "a very loud wake-up call" in a fundraising email to supporters.
Heading into the debate, Sanders was eager to lower expectations for his finish in New Hampshire, casting himself as an underdog against "the most powerful political organisation in the country."
Clinton, for her part, signalled her determination to at least narrow the gap before Tuesday's vote in the state where she defeated Barack Obama in 2008 before ultimately losing the nomination to him.
Her prospects are much stronger in primaries and caucuses after New Hampshire, as the race moves on to states with more diverse electorates that are to her advantage.
The Durham debate is the first face off for Clinton and Sanders since former Maryland Governor Martin O'Malley dropped out of the race after a poor showing in Iowa.
