WASHINGTON -- Education Secretary Arne Duncan told members of the Senate Budget Committee on Tuesday that he was "hopeful" a deal could be reached to prevent the interest rate on new federally subsidized student loans from doubling in less than two weeks. The hearing was on the administration's budget request for the 2014 fiscal year, which included a plan to switch to a market-based interest rate. Some Democratic senators expressed skepticism about the plan, saying they don't want rates to increase above current levels, while Republicans said their plan -- introduced before the administration's budget request -- was very similar to the president's. "I think there are some differences, but I think they're resolvable," Duncan said. "I am very hopeful that this can get done."