US Democratic presidential front-runner Hillary Clinton vowed on Saturday not to raise taxes on middle-class Americans if elected next November in a populist push to position herself for a general election battle on pocket-book issues.
Clinton, at a debate with rivals Bernie Sanders and Martin O'Malley, repeatedly zeroed in on Republican presidential front-runner Donald Trump, at one point accusing him of helping Islamic State militants recruit new members with his vow to ban Muslims from entering the United States.
The two-hour debate, moderated by ABC News, did not appear to change the trajectory of the 2016 Democratic race for the White House, with Clinton hanging on to a big lead in polls of Democratic voters and Vermont Senator Sanders and former Maryland Governor O'Malley still searching for breakthrough moments.
Clinton questioned the affordability of some of Sanders' proposals such as creation of a single-payer healthcare system and tuition-free college, suggesting these plans would lead to higher taxes on working families.
She pledged not to raise taxes for middle-class families and said such a tax "should not be part of anybody's plan right now".
"I don't think we should be imposing big new programs that are going to raise middle-class families' taxes," the former secretary of state said. "We've got to get back to where people can save money again, where they can invest in their families."
Sanders, seeking to bite into Clinton's big lead in polls of Democratic voters, criticised her for supporting the speedy departure of Syrian President Bashar al-Assad, who has resisted all diplomatic efforts to leave power with a civil war raging in his country and swathes of territory controlled by Islamic State, also known as Isis.
"Secretary Clinton is too much into regime change and a little bit too aggressive without knowing what the unintended consequences might be," Sanders said. "Yes, we could get rid of Assad tomorrow, but that would create another political vacuum that would benefit Isis."
"Regime change is easy. Getting rid of dictators is easy. But before you do that, you've got to think about what happens the day after," said Sanders, a democratic socialist.
Clinton rejected the criticism and pointed out that Sanders as a US senator from Vermont had voted "for regime change with respect to Libya" in 2011.
And she disagreed with Sanders' assertion that the US military should prioritise the fight against Islamic State over working to get Assad to leave power, saying both should be done at the same time.
"We will not get the support on the ground in Syria to dislodge Isis if the fighters there — who are not associated with Isis, but whose principal goal is getting rid of Assad — don't believe there is a political diplomatic channel that is ongoing. We now have that," Clinton said.
