A few names come to mind: Jerry Pournelle, Larry Niven, Ben Bova, Keith Laumer, Gene Wolfe, Gordon Dickson, Dean Ing, David Drake, Robert Heinlein (up to about Stranger in a Strange Land, then he went to Hell). A lot of these writers were somewhere in the conservative to libertarian range, but as you can see there is a shortage of *living* contemporary conservative SF writers. As with actors in Hollywood, it’s not that there aren’t writers whose personal politics aren’t conservative, but most learn early on that they’d better keep their mouths shut if they want to have a career. The Fruits & Nuts Faction did a really good job of making examples of Orson Scott Card and J.K. Rowling. Aside from people like Jon Del Arroz, who seems to thrive on it, no one wants to draw the attention of the crazies.
Unfortunately most of those people are dead.😵