I know, it is surprising.
You would figure there would be atleast one...

I don't know....
Here's an interesting site called "The Political Graveyard" I just came across on "politicians who committed suicide.
politicalgraveyard.com...
John Quincy Adam's son did apparantly. Didn't know that.....
I noticed one of the Kennedy's, in 1871 John Fitzgerald took strychnine.
Most interesting one so far

is Preston King, 1865:
"Tied bags of lead shot to his body, jumped from the ferryboat Paterson, between New York and Hoboken, and drowned in the Lower Hudson River,
November 12, 1865."
That's quite the elaborate plan.
Most are self inflicted gunshot wounds.