Democratic frontrunner Hillary Clinton and Sen. Bernie Sanders (D-Vt.) clashed Sunday over key issues like gun control and Wall Street in the last presidential debate before the Feb. 1 Iowa caucuses. Sanders accused Clinton of being too close to Wall Street, a major source of her campaign contributions. Clinton tried to puncture the grassroots appeal that has helped Sanders surge in the polls, saying he had voted “with the NRA” several times against gun control. The third candidate, low-polling former Maryland governor Martin O’Malley, said both his rivals had been “inconsistent” on gun control while he signed sweeping gun laws.