What principles? In Texas he expanded the government dramatically and, when it came time to appoint vacancies to the Texas Supreme Court, appointed jurists who moved it to the left. His first proposal in Washington was to expand the Department of Education while cheerfully ensuring a new, friendlier tone by going along with the Democrats. He has thrown the conservatives who elected him a few bones (miniscule tax cuts, appointments to the courts - none of whom he'll fight for), a limited amount of red meat to chew on (Defense increases) and a better posture on the 2nd Amendment which he allowed his appointment John Magaw to promptly toss in the ash heap the first time they had a chance to back it up by allowing pilots to be armed.
Face it, the guy's a Rockefeller Republican. He believes in government and, while he doesn't want to say so, knows taxes will eventually have to go up to pay for it all. If the Democrats are smart enough to nominate someone who can successfully pretend he's a moderate, Bush could easliy wind up back in Texas in '04.