Democrat Hillary Clinton went on the attack against rival Bernie Sanders on Thursday in their most contentious presidential debate yet, questioning whether his ambitious proposals were viable and saying it was unfair to question her liberal credentials.
Sanders fought back repeatedly, accusing Clinton of representing the political establishment during a debate that featured sharp differences over healthcare, college tuition funding and efforts to rein in Wall Street.
The intensity of the exchanges reflected a race that has seen Clinton's once prohibitive lead shrivel against a relatively unknown underdog in the battle over who would best lead the Democratic Party in the Nov. 8 election and who could deliver on the party's liberal agenda.
Clinton said Sanders' proposal for single-payer universal healthcare coverage would jeopardize Obamacare, calling it "a great mistake," and she said his plans for free college education would be too costly to be realistic.
"I can get things done. I'm not making promises I can't keep," Clinton said.
Sanders said he would not dismantle Obamacare but would expand it, pointing to how many other countries provide universal healthcare.