Guns the choice in most assassination attempts
Four presidents – Lincoln, Garfield, McKinley and Kennedy – were killed by gunfire. Eleven other presidents were targeted by assassins: Jackson, Theodore and Franklin Roosevelt, Truman, Nixon, Ford (twice), Carter, Reagan, the two Bushes and Clinton. Of these 11, pistols and rifles were the weapons of choice in all but three: Nixon and the two Bushes.
Since the presidency of Franklin Roosevelt, only Eisenhower and Johnson were not known to have been nearly assassinated or assassinated. Sometimes attempts are not uncovered, but fail for other reasons.(Many attempts at the assassination of Hitler were bungled.)
As for President Obama, facts are not known.
As far as we know, all assassins or attempted assassins were men, except for the two women who tried to kill Gerald Ford. This squares with the psycho-biology of the male, who has always had a greater tendency toward homicide.
The good news about guns is that no American government would ever try to confiscate part of our bank accounts, as is being tested in Cyprus.