In their first clash since Bernie Sanders delivered a 22-point drubbing to Hillary Clinton in New Hampshire primary, the latter sought to portray her challenger for Democratic presidential nomination as an unrealistic talker.
Hoping to arrest her self-styled Democratic Socialist rival's surging popularity before the next nominating contests in Nevada and South Carolina, Clinton asked him to level with people on his trillion dollar plans for universal healthcare and free college education.
Meeting in Milwaukee, Wisconsin, Thursday for the Democratic debate, they agreed on most issues -- a path to citizenship for undocumented immigrants and an overhaul of the criminal-justice system they believe treats blacks and Latinos unfairly.
But they differed sharply over the methods to reach their goals, with Clinton trying to attack Sanders for not being supportive enough of President Barack Obama against whom she herself made a unsuccessful bid for the Democratic nomination back in 2008.
"Have you ever disagreed with a president? I suspect you may have," Sanders countered, describing his disagreements with Obama as normal between friends and allies.
But when she accused Sanders of calling Obama "weak" and a "disappointment" in the past and suggested "the kind of criticism that we heard from Sen. Sanders about our president, I expect from Republicans," he was furious.
"Madam Secretary, that is a low blow," Sanders retorted, reminding Clinton that "One of us ran against President Obama. I was not that candidate."
At another point, he warned Clinton: "You are not in the White House yet."
Both candidates also made strenuous efforts to show they appreciate economic and social problems afflicting African-American communities.
"An African-American baby born today stands a one in four chance of ending up in jail," Sanders said. "That is beyond unspeakable."
Sanders also suggested that race relations would "absolutely" be better under his administration than in Obama's tenure.
There was also a spirited exchange between Clinton and Sanders over foreign policy as she sought to drive home an argument that only she has the qualities demanded of a commander-in-chief.
Sanders revived his attack on Clinton's 2002 vote to authorise the Iraq War to argue that judgement -- not experience -- is most important in a commander in chief.
Clinton hit back that a vote 14 years ago does not equate to a plan to destroy IS in 2016.
Sanders also took a swipe against Clinton for taking the advice of Henry Kissinger, whom he called "one of the most destructive secretaries of state in the modern history of this country".
"I am proud to say that Henry Kissinger is not my friend," he said. Clinton responded by suggesting that Sanders is weak on foreign policy and is unwilling to disclose who is advising him on national security.
"Well, I know journalists have asked who you do listen to on foreign policy, and we have yet to know who that is," Clinton said.
Sanders also hit Clinton over the fact that a super PAC -- a political action committee that can raise unlimited funds -- supports her campaign. The Vermont senator has argued that because Clinton accepts contributions from financial groups, she is less likely to take on Wall Street in office.
She countered that despite accepting such donations in 2008, Obama passed tough new regulations on the financial industry early in his administration and she would do the same.
But Sanders told her: "Let's not insult the intelligence of the American people. People are not dumb."
(Arun Kumar can be contacted at arun.kumar@ians.in)
