Hillary Clinton just can’t say “no” to a White House run as the former Democratic nominee refused to rule out a challenge to President Trump in 2020.The former secretary of state was speaking on a radio interview on Tuesday when she said people were urging her to enter the contest amid a lackluster Democratic field.“I, as I say, never, never, never say never,” Clinton told BBC Radio 5 Live.However, the 2016 presidential candidate insisted she was not planning on a run — at the moment.