Author/journalist Lou Dubose does some of the best, most thorough reporting on Tom DeLay and DeLay Inc. This morning he has a long piece in Salon (which you can read if you have a subscription or watch a trailer to a movie to get a day pass).
Here's Lou's quick answer to why DeLay is still in power:
The answer to that question involves the two constituencies most indebted to Tom DeLay: The Republican members of the House who selected him to lead them in 2003 and (for the moment) continue to support him; and the Republican campaign and advocacy groups enriched by huge contributions from the same corporate lobbyists and clients who pick up the tab for DeLay, his family and staff to play golf in American Saipan, Scotland, England and Russia.
There's lots of evidence to back this up, which he writes up throughout the piece.
Here's how he concludes:
Will DeLay survive? He brings in millions of dollars and is an indefatigable party builder who last year added six Texas seats to the Republican House majority by redrawing congressional district lines in Texas. So it's hard for House Republicans to say goodbye. But as DeLay's name becomes synonymous with political corruption, they might have no choice. If the party decides DeLay is too much a liability to carry into the off-year elections, a delegation of his colleagues will pay him a visit at his Capitol office just off Statuary Hall and thank him for all he's done for the party.