Dear Rabbi Simon,
Rashi sometimes refers to “the king messiah” and at other times just to “the messiah”. Why? Is there any significance in the distinction?
Thank you for your question.
Rashi is exceedingly exacting in his language, so I would expect that there is indeed a “significance”. However it is likely that the explanation lies in the specific context, and does not necessarily carry eschatological significance. Ultimately mashiach is shorthand for the descendant of the seminal “anointed of G-d” (through the prophet Samuel) which is King David.
So the Redeemer will be both “anointed” and King, by virtue of his pedigree.
This is why all messianic pretenders and aspirants seek to associate themselves with the Davidic line.
I hope this is helpful in some way.
Rabbi Rashi Simon