Clinton wanted it killed because Texas didn't go for him in the '92 election and he essentially admitted as much in a later interview. As for it being over budget, that story was put to rest much later after an exhaustive GAO audit showed that it was well UNDER budget when Clinton pulled the plug. As a matter of fact, Clinton spent MORE to PLUG the hole (which was ~2/3rds complete) than had been spent to dig it and develop the technology that was to be used with it.
Additionally, Clinton REFUSED to allow the state to purchase the SCSC and operate it independent of the government or any government funding. It doesn't make any sense that "big oil" would be behind the move to kill it in a state where "big oil" is "BIG OIL". In theory, the SCSC would have no products or services that would alter or change anything that big oil does.
I have a friend that will disagree with you on that point. He claims (he's the PHD in physics, not me) that the answer to fusion will be found in one of these devices, and that the one being built in Texas was the only one large enough to possibly unlock the mystery. (His contention is that the ones in Europe are not large enough).
As far as the killing of it goes, sadly there WERE many other hands on the dagger. That moron leatherface governor we had in Texas at the time deserves part of the blame.
One of my friends had a machining company that did a lot of work on that project, and he told me it was dead in 1992. In fact, and I almost fainted because this guy is more of a right wing gun nut than I am, he actually wondered if Clinton winning (the election had not be held yet) might save the thing because the Bush administration had been so lukewarm towards it.