Can't Rebind "C-d" in Emacs

Question

In smartparens (in elisp), we have 'sp-kill-sexp. Now, if I call M-x my-func [enter], then 'sp-kill-sexp gets executed as expected.

However, I can't seem to bind that function to "C-d". So the below does not work. Is there some trick to getting my "C-d" key binding to work?

(global-set-key (kbd "C-d") 'sp-kill-sexp)

And neither this SO post, nor this one, seem to work. None of these pairs binds C-d to 'sp-kill-sexp. Any insights?

(global-set-key (kbd "<delete>") 'sp-kill-sexp)
(global-set-key (kbd "C-d") 'sp-kill-sexp)

(global-set-key (kbd "<delete>") 'sp-kill-sexp)
(global-set-key [(control d)] 'sp-kill-sexp)

(global-set-key (kbd "<delete>") 'sp-kill-sexp)
(global-set-key (kbd "\C-d") 'sp-kill-sexp)

Answer 1

Ok, finally got this sorted. I must have had other things that were trampling on my keybindings. I commented everything out, and just put in the bare essentials. Now I'll build on top of that. Thanks for all the help.

Here's what I have so far, with working bindings.

http://pastebin.com/uaUF7n3x