USA's tag line is "characters welcome." All their shows have quirky characters. A Star Trek show could be created that fit the USA style, but it would feel different classic Trek. A better network thematically would be SyFy or TNT.
On the flip side, the viewer argument for USA looks even stronger if you look at Burn Notice viewers not USA averages. The first half of this Burn Notice season all had more than 5m viewers. The first half finale peaked at 7.6m viewers. Enterprise by contrast dropped below 5m in early season 2 and dropped below 7.6m after Terra Nova(1x06). So a successful USA show can expect to attract enough viewers to be sustainable.
On TNT, Leverage seems to be drawing about 3.5m viewers. I'm having trouble tracking down ratings for SyFy shows, but I think I remember BSG peaking a little over 3m and beating Enterprise. So either TNT or SyFy may be able to sustain a large enough audience, but it'll be tougher than USA. Although they all should have roughly the same coverage.