Radio Amateur Civil Emergency Service (RACES) was memorialized in the FCC Part 97 as a standby radio service for the government. It is comprised of amateur radio operators but is organized by local municipal and county governments. RACES members must be registered with the government before they can operate on a RACES team.
Repeaters listed by RepeaterBook can be tagged as an RACES-affiliated repeater.
The primary difference between ARES and RACES is that ARES is organized by amateur radio operators who make their services available to local governments and RACES is organized by the government itself.
By FCC rule, both ARES and RACES members must be unpaid volunteers while operating on amateur radio frequencies.
It is possible, under the War Powers Act, that the amateur radio service could be suspended, even forcing the cessation of amateur radio use by ARES members, but allowing RACES to continue in service. RACES does require an emergency declaration by the government to operate. According to Wikipedia, many ARES members also register as RACES members.