If you use a graphical login you should not edit .xinitrc.
If you use Gnome's login (which i believe is standard for redhat) you should first look up where gdm stores it's session scripts, for me it's:
then copy eg the Windowmaker script and rename it to Enlightenment, edit it and change windommaker to enlightenment. Make the script executable (if it isn't)
After that open /etc/X11/xdm/Xsession and search for something like:
gkrellm -w &
Yours probably won't look the same, add enlightenment as one of the options:
I am not shure if this is going to work but i believe so, I am not using redhat (slackware 9) nor gdm (kdm) so can't test it. Actually i can test gdm but i'm to lazy, i will change to it soon anyway.
Hope you understand