Candidates for the Democratic race for the White House have clashed on gun control and healthcare in their liveliest TV debate so far.Hillary Clinton attacked Bernie Sanders` record on gun control, and said his healthcare plan risked derailing recent legislation.Mr Sanders accused Mrs Clinton of being in the pocket of financial institutions responsible for the 2008 crisis.While Mrs Clinton leads nationwide, Mr Sanders is a threat in key states.Hours before the debate in South Carolina, Mr Sanders - a Vermont senator - had unveiled a healthcare plan for all American citizens.This was the final Democratic debate before caucuses in Iowa on 1 February show who the state`s voters prefer as their candidate.Former Maryland Governor Martin O`Malley, who is trailing Mrs Clinton and Mr Sanders in polls, also took part in the lively debate in which personal attacks were few and far between.Mr Sanders announced his universal healthcare plan two hours before the debate started.-It would see citizens pay what he called "a 2.2% income-based premium" towards healthcare-Companies would pay an extra 6.2% of an employee`s income towards the planMr Sanders` campaign website said it was a way to "stop forcing working Americans to choose between bargaining for higher wages or better health insurance".-Mrs Clinton said any moves to scrap the current Affordable Healthcare Act risked plunging the Democrats into "contentious debate". Instead, the party should work on improving the programme, known as Obamacare.Mr Sanders responded: "Nobody is tearing this up." He said he wanted to build on Obamacare.