Alan Dershowitz expressed doubt on Monday that federal prosecutors could make a case for attempted murder against the man accused of trying to assassinate former President Donald Trump on Sept. 15. Secret Service agents thwarted the apparent assassination attempt on Trump by firing shots at Ryan Wesley Routh, who was allegedly lurking near Trump International Golf Club, two months after Trump was shot in the right ear while giving a speech at a July campaign rally in Pennsylvania. Dershowitz said that despite Routh’s intent to kill Trump, it was not clear that all of the legal elements for att…