The “Star Wars” term was actually derogatory. The things Reagan had in mind were technologically impossible.
No – some of them (like Edward Teller’s “third generation” nukes, or Daniel O. Graham’s “High Frontier” designs were certainly technologically possible. They just didn’t do exactly what Reagan thought or wanted them to do.
And often were technologically possible like commercially viable fusion power plants are; in the sense of “physics allows it but we have no real idea how long it would take to get from here to there if we even can”. It’s decades later and we still don’t have a bomb pumped x ray laser, for example.
Daniel O. Graham’s plan used mostly off-the-shelf technology requiring no technological breakthroughs. The problem is, it didn’t protect people and cities – just hardened military targets.
As for the nuclear-pumped x-ray laser, they demonstrated operation of the principle in underground testing. But nobody ever designed and built a working model because who really wanted it, and would pay. The more you looked at Teller’s device, the more obvious it became that it wasn’t really an answer to anyone’s intended mission.