U.S. First lady Jill Biden has hit back at Republican presidential candidate Nikki Haley's call for elderly politicians to take a mental competency test. During an interview with CNN, Jill Biden described Haley's proposal as 'ridiculous' and cited the American president's latest surprise trip to Ukraine to vouch for his competency. Haley, who is the Republican party's first Indian-origin presidential candidate, put forth the proposal when she announced her candidacy last month. She has been slammed for the proposal which has been termed 'absurd.'