It rare to find a Republican willing to sacrifice his career for the good of the party. And besides DeLay has a lot of legal bills to pay off - not something easily done on a House member's salary. In addition, it drains out the momentum from the Democrats drive to take back the House - an easily identifiable symbol of Republican excess and corruption is gone. The Democrats managed to get rid of DeLay but they'll probably wish they had him to kick around. Its like the old saying goes that in their case, no good deed goes unpunished.
(Denny Crane: "I Don't Want To Socialize With A Pinko Liberal Democrat Commie. Say What You Like About Republicans. We Stick To Our Convictions. Even When We Know We're Dead Wrong.")
"In addition, it drains out the momentum from the Democrats drive to take back the House - an easily identifiable symbol of Republican excess and corruption is gone."
A six year term limit would effectively take care of that problem, without taking his fellow encumbants to the brink.